Coffee and walnut cake is one of those combinations where you wonder, briefly, why you ever ate cake without both of these things happening simultaneously. Vegan coffee walnut cake takes that classic British pairing espresso-infused sponge, chopped walnuts throughout, coffee buttercream frosting, candied walnut garnish and delivers it completely plant-based in a two-layer 8-inch round that serves 16 people at 603 calories per slice. The candied walnuts on top are genuinely the detail that makes this cake look like it came from a serious bakery. They take 7 minutes to make.
I started making this vegan walnut cake when I wanted something that felt genuinely adult and sophisticated for a dinner party dessert something that would sit naturally alongside good coffee rather than competing with it. The espresso in the batter doesn’t just flavor the cake; it deepens the walnut’s natural bitterness and creates a complex, slightly roasted quality throughout every bite. The brown sugar adds a molasses warmth. The vegan buttermilk creates a tender, fine-crumbed sponge that holds up beautifully under the weight of the coffee frosting. This is the cake for people who have moved past sprinkles.
My Recipe Timing and Serving Details
Here’s your complete planning overview for the two 8-inch cake version (serves 16):
| Detail | Info |
| Prep Time | 30 minutes |
| Bake Time | 35–45 minutes |
| Cooling Time | 10–15 minutes in pan + full cooling |
| Candied Walnut Time | 7–10 minutes |
| Total Time | ~1 hour 15 minutes + cooling |
| Servings | 16 slices |
| Serving Size | 1 slice |
| Calories Per Slice | 603 kcal |
| Course | Dessert |
| Diet | 100% Vegan |
This vegan coffee walnut cake serves 16 people as substantial, celebration-worthy dessert slices. At 603 calories per slice (including the coffee buttercream frosting and candied walnuts), this is a genuinely indulgent celebration cake calibrated for occasions where the dessert is meant to be memorable. The recipe includes both a single 8-inch version and the doubled recipe for two 8-inch layers the ingredients listed here are for the two-layer version that serves 16.
Why This Specific Combination Works
Coffee and walnut cake has been a fixture of British baking for decades, and the pairing works for reasons that go beyond tradition:
Coffee amplifies walnut’s natural bitterness- in a way that makes both taste more complex. Walnuts have a slight astringency and bitterness from their tannins coffee contains similar bitter compounds. When these two ingredients share a batter, they reinforce each other’s depth rather than competing. The resulting cake tastes richer and more developed than the ingredient list might suggest.
Brown sugar specifically- adds a caramel-molasses note that bridges coffee’s roasted bitterness with walnut’s nuttiness. White sugar would produce a cleaner, more neutral cake. Brown sugar creates a third flavor dimension that makes the cake feel genuinely complex.
Vegan buttermilk – made from plant milk and apple cider vinegar creates the tender, slightly tangy sponge that gives this cake its characteristic texture. The acid from the buttermilk activates the baking soda and produces a fine, even crumb that absorbs the espresso moisture without becoming heavy.
FYI the recipe uses olive oil specifically as an option alongside neutral oils. Extra virgin olive oil’s slightly fruity, grassy character works surprisingly well against the coffee and walnut flavors it adds a subtle complexity that sunflower oil doesn’t. If you’re curious, try it once before deciding it sounds wrong. It works.
Full Ingredient List Two 8-Inch Layer Cake (Serves 16)
The Cake:
- 150g (1½ cups) walnuts, finely chopped
- 400g (3 cups + 3 tablespoons) all-purpose flour, sifted
- 330g (1½ cups) soft brown sugar
- 3¾ teaspoons baking powder
- ¾ teaspoon baking soda
- ½ teaspoon sea salt
- 180ml (¾ cup) espresso or strong coffee -cooled to room temperature
- 1½ batches (360ml) vegan buttermilk
- 180ml (¾ cup) olive oil or neutral oil
- 1½ tablespoons vanilla extract
The Candied Walnuts:
- 200g (2 cups) walnut halves
- 2 tablespoons soft brown sugar or granulated sugar
- 1 tablespoon vegan butter or olive oil
Frosting:
- 1 batch vegan coffee buttercream – see notes
Making the Vegan Buttermilk
The 1½ batches of vegan buttermilk means 360ml total, made from plant milk and apple cider vinegar:
Combine 350ml of plant-based milk (oat or soy work best) with 1½ tablespoons of apple cider vinegar or lemon juice. Stir and allow to rest for 10 minutes the mixture curdles slightly as the acid reacts with the milk proteins, creating a thick, slightly tangy liquid that functions as buttermilk in the batter.
The Coffee Specification
The recipe calls for cooled espresso or strong coffee and the specification that it’s at room temperature is important. Hot coffee added to a batter with oil and sugar can cause the fat to separate and the sugar to partially cook. Room temperature coffee incorporates smoothly. Make your espresso or strong coffee first, allow it to cool completely, then proceed.
Espresso vs. strong coffee- Espresso produces a more concentrated, more intensely coffee-flavored cake. Strong brewed coffee (cold brew concentrate is excellent) produces a slightly milder result. Both work choose based on how coffee-forward you want the finished cake to taste.
Equipment You’ll Need For
Primary Equipment
- Two 8-inch (20cm) round cake pans – lined with parchment circles and liberally greased on the sides. Liberal greasing matters the walnut pieces in the batter can stick to insufficiently greased sides.
- Oven at 160°C/320°F fan (180°C/356°F conventional) – the recipe provides both settings. The lower fan-forced temperature prevents the top from over-browning before the center sets, which is particularly important given the brown sugar content brown sugar caramelizes and browns faster than white sugar at high temperatures.
- Wire cooling racks – one per layer, for complete cooling before frosting
Mixing Equipment
- Large mixing bowl – for dry ingredients and final batter (the two-layer version has substantial volume)
- Separate medium bowl – for wet ingredients
- Whisk – for combining dry ingredients and wet ingredients separately, then the final batter
- Kitchen scale – the recipe specifically and strongly recommends gram measurements for accuracy
For Candied Walnuts
- Small heavy-bottomed skillet or saucepan – for candying the walnuts
- Parchment paper sheet -for cooling the candied walnuts
- Wooden spoon or silicone spatula -for constant tossing during the candying process
For Assembly
- Offset spatula– the essential tool for the three-stage frosting application (between layers, exterior coat, piped top)
- Piping bag with a round or star tip – for the piped frosting layer on top
- Cake stand or serving plate
Step-by-Step Instructions For
Step 1 – Preheat and Prepare
Preheat the oven to 160°C/320°F fan or 180°C/356°F conventional. Line the base of both cake tins with parchment circles and liberally grease the sides with oil or vegan butter.
If you haven’t already made and cooled your espresso/coffee, do that now it must be at room temperature before use.
Step 2 – Make the Vegan Buttermilk
Combine the plant milk and apple cider vinegar, stir, and set aside for 10 minutes while you prepare everything else.
Step 3 – Mix Dry Ingredients
In your large mixing bowl, whisk together the finely chopped walnuts, sifted flour, brown sugar, baking powder, baking soda, and sea salt until evenly combined. The walnuts distribute through the flour at this stage they’ll stay suspended throughout the batter and bake evenly distributed through the cake.
Finely chopping the walnuts is specifically required roughly chopped walnuts create large gaps in the cake’s crumb structure and uneven texture. Aim for pieces no larger than ¼ inch. A food processor produces the most consistent fine chop in seconds.
Step 4 – Mix Wet Ingredients
In a separate medium bowl, whisk together the cooled espresso, vegan buttermilk, olive oil, and vanilla extract until uniformly combined.
Step 5 – Combine and Bake
Pour the wet ingredients into the dry ingredients. Whisk until no visible pockets of flour remain be careful not to over-mix beyond this point. Over-mixing develops gluten and produces a tough, dense cake. The moment the dry flour disappears, stop.
Divide the batter evenly between the two prepared tins. Bake for 35–45 minutes until a toothpick inserted into the center comes out clean.
Allow to cool in the pans for 10–15 minutes, then transfer to wire racks to cool completely. Refrigerate the cooled layers in an airtight container until ready to assemble.
Step 6 – Make the Candied Walnuts
While the cake bakes and cools, add the 200g walnut halves, 2 tablespoons of sugar, and 1 tablespoon of vegan butter or olive oil to a skillet over medium-low heat. Cook for 5–7 minutes, tossing constantly this constant movement prevents the sugar from burning on the walnut surfaces.
The candying is complete when the sugar has fully melted and caramelized around the walnuts, they’re evenly golden and fragrant, and the mixture is dry rather than wet.
Transfer immediately to a parchment-lined surface and spread out to cool they stick together if left in a pile. Once cool, separate: reserve 16 walnut halves for the individual top decorations and chop the remaining walnuts for filling and crumble garnish.
Step 7 – Assemble the Cake
First layer- Place the first cake layer on your serving plate or cake stand. Spread approximately ⅓ of the coffee buttercream evenly across the top surface. Scatter half of the chopped candied walnuts over the frosting press them gently into the frosting surface so they stay in place when the second layer is added.
Second layer- Place the second cake layer on top. Use your offset spatula to coat the sides and top of the entire cake with approximately another ⅓ of the frosting. This is the exterior coat it doesn’t need to be perfectly smooth for the final result to look impressive, but a consistent, even coverage creates the right backdrop for the decorative top.
Top decoration- Transfer the remaining ⅓ of frosting to a piping bag and pipe across the top of the cake in your preferred pattern. Place the 16 reserved candied walnut halves evenly around the top one per intended serving slice, which guides portioning. Sprinkle the remaining chopped candied walnuts across the piped frosting.
The Vegan Coffee Buttercream
The recipe calls for a separate vegan coffee buttercream recipe. Here’s the standard approach:
Components:
- 2 cups vegan butter (Earth Balance, Miyoko’s, or Violife) , at room temperature
- 4–5 cups powdered sugar, sifted
- 2–3 tablespoons espresso or strong coffee , cooled
- 1 teaspoon vanilla extract
- Pinch of sea salt
Method- Beat the room temperature vegan butter on medium-high for 2–3 minutes until pale and fluffy. Add sifted powdered sugar ½ cup at a time, beating on low after each addition. Add the cooled espresso, vanilla, and salt. Beat on high for 3–4 minutes until the frosting is light, fluffy, and coffee-colored throughout.
Consistency adjustment- Too thick add cooled espresso 1 tablespoon at a time. Too thin add powdered sugar 2 tablespoons at a time.
FYI the coffee flavor in the buttercream should be pronounced enough to complement the coffee in the cake layers without being overwhelming. Taste as you add the espresso and stop when the coffee flavor is clearly present but not aggressive. IMO, under-coffeeed buttercream is a bigger problem than over-coffeed buttercream for this specific cake.
Brown Sugar’s Role in This Cake
The choice of soft brown sugar over granulated white sugar in this recipe is deliberate and produces a meaningfully different cake:
Molasses content in brown sugar- Brown sugar is granulated sugar with molasses partially reincorporated. The molasses adds moisture, a slightly caramel-butterscotch quality, and a darker color to the baked crumb.
Interaction with coffee- The molasses in brown sugar and the bitter roasted compounds in coffee share similar flavor origins both derive from the Maillard reaction in roasting/caramelizing. They reinforce each other’s depth rather than competing, making the cake taste more complex than it would with white sugar.
Moisture retention- Brown sugar’s hygroscopic nature (it attracts and holds moisture from the air) keeps the cake moist longer than white sugar cakes. This vegan coffee walnut cake stays excellent for the full 4–5 day refrigerator storage period partly because of the brown sugar’s moisture-holding properties.
The Coffee Quantity Guide
The recipe uses ¾ cup of espresso/strong coffee for the two-layer version. This quantity provides noticeable, pleasurable coffee flavor without making the cake taste like a coffee beverage in solid form.
Adjusting coffee intensity:
- More coffee-forward- Increase by 2–3 tablespoons (maximum ¼ cup additional) and reduce oil by the same amount to maintain liquid balance
- More subtle coffee note- Use strong filter coffee rather than espresso
- Maximum coffee intensity- Use cold brew concentrate (typically 2x strength) at the same quantity
- Caffeine-free version- Use chicory coffee or a dark, strong coffee substitute the roasted, bitter flavor of chicory works particularly well with walnut
Try It Next recipe
Nutrition Information Per Slice
At 603 calories per slice (with frosting and candied walnuts):
| Nutrient | Per Slice |
| Calories | 603 kcal |
| Carbohydrates | 67g |
| Protein | 8g |
| Fat | 35g |
| Fiber | 2g |
| Sugar | 35g |
| Sodium | 241mg |
| Potassium | 553mg |
| Calcium | 127mg |
| Iron | 4mg |
8 grams of plant-based protein from the combination of walnuts, flour, and vegan butter in the frosting. The 35 grams of fat comes primarily from walnuts (omega-3 rich polyunsaturated fat) and the oil used in the batter, a meaningful portion of healthy fat for a celebration cake. 553mg of potassium per slice reflects the walnut content throughout.
Storage
- Refrigerator- Store in an airtight container for 4–5 days. Remove 1 hour before serving the recipe specifically notes this to allow the cake and frosting to soften to optimal serving texture.
- Freezer- Freeze individual leftover slices in airtight containers. Thaw in the refrigerator overnight and bring to room temperature before serving.
- The cake tastes best fresh – the recipe is explicit about this. Plan to serve on the day it’s assembled or the following day for the best result.
My Final Thoughts
Vegan coffee walnut cake is the dessert that makes after-dinner coffee a complete ceremony the cake alongside, the candied walnuts on top, the coffee buttercream between the layers. 603 calories per slice, 16 people served, completely plant-based, and the most sophisticated thing on any dessert table where it appears.
The candied walnuts take 7 minutes. Make them. They’re worth every second.
Bake the layers, make the buttercream, candy the walnuts, assemble with intention. Then serve alongside the best coffee you have.
Vegan Coffee Walnut Cake The Rich, Sophisticated Layer Cake
Ingredients
Equipment
Method
- Step 1 – Preheat and Prepare
- Preheat the oven to 160°C/320°F fan or 180°C/356°F conventional. Line the base of both cake tins with parchment circles and liberally grease the sides with oil or vegan butter.
- If you haven’t already made and cooled your espresso/coffee, do that now it must be at room temperature before use.
- Step 2 – Make the Vegan Buttermilk
- Combine the plant milk and apple cider vinegar, stir, and set aside for 10 minutes while you prepare everything else.
- Step 3 – Mix Dry Ingredients
- In your large mixing bowl, whisk together the finely chopped walnuts, sifted flour, brown sugar, baking powder, baking soda, and sea salt until evenly combined. The walnuts distribute through the flour at this stage they’ll stay suspended throughout the batter and bake evenly distributed through the cake.
- Finely chopping the walnuts is specifically required roughly chopped walnuts create large gaps in the cake’s crumb structure and uneven texture. Aim for pieces no larger than ¼ inch. A food processor produces the most consistent fine chop in seconds.
- Step 4 – Mix Wet Ingredients
- In a separate medium bowl, whisk together the cooled espresso, vegan buttermilk, olive oil, and vanilla extract until uniformly combined.
- Step 5 – Combine and Bake
- Pour the wet ingredients into the dry ingredients. Whisk until no visible pockets of flour remain be careful not to over-mix beyond this point. Over-mixing develops gluten and produces a tough, dense cake. The moment the dry flour disappears, stop.
- Divide the batter evenly between the two prepared tins. Bake for 35–45 minutes until a toothpick inserted into the center comes out clean.
- Allow to cool in the pans for 10–15 minutes, then transfer to wire racks to cool completely. Refrigerate the cooled layers in an airtight container until ready to assemble.
- Step 6 – Make the Candied Walnuts
- While the cake bakes and cools, add the 200g walnut halves, 2 tablespoons of sugar, and 1 tablespoon of vegan butter or olive oil to a skillet over medium-low heat. Cook for 5–7 minutes, tossing constantly this constant movement prevents the sugar from burning on the walnut surfaces.
- The candying is complete when the sugar has fully melted and caramelized around the walnuts, they’re evenly golden and fragrant, and the mixture is dry rather than wet.
- Transfer immediately to a parchment-lined surface and spread out to cool they stick together if left in a pile. Once cool, separate: reserve 16 walnut halves for the individual top decorations and chop the remaining walnuts for filling and crumble garnish.
- Step 7 – Assemble the Cake
- First layer- Place the first cake layer on your serving plate or cake stand. Spread approximately ⅓ of the coffee buttercream evenly across the top surface. Scatter half of the chopped candied walnuts over the frosting press them gently into the frosting surface so they stay in place when the second layer is added.
- Second layer- Place the second cake layer on top. Use your offset spatula to coat the sides and top of the entire cake with approximately another ⅓ of the frosting. This is the exterior coat it doesn’t need to be perfectly smooth for the final result to look impressive, but a consistent, even coverage creates the right backdrop for the decorative top.
- Top decoration- Transfer the remaining ⅓ of frosting to a piping bag and pipe across the top of the cake in your preferred pattern. Place the 16 reserved candied walnut halves evenly around the top one per intended serving slice, which guides portioning. Sprinkle the remaining chopped candied walnuts across the piped frosting.
Notes
Nutrition Information Per Slice
At 603 calories per slice (with frosting and candied walnuts):| Nutrient | Per Slice |
| Calories | 603 kcal |
| Carbohydrates | 67g |
| Protein | 8g |
| Fat | 35g |
| Fiber | 2g |
| Sugar | 35g |
| Sodium | 241mg |
| Potassium | 553mg |
| Calcium | 127mg |
| Iron | 4mg |
Hi — I’m Rachel. I’m a wife, a mom, and a home cook who believes that food should bring comfort, joy, and compassion to the table. I live with my family — two hungry little foodies who are my most honest recipe testers — and together we’ve built a kitchen culture that’s all about good food that happens to be 100% vegan. I started this blog because I wanted a place to share the recipes that keep our days moving, the dishes that make weeknights feel a little easier, and the meals that become our little family traditions.