Step 1- Preheat and Prepare the Pan
Preheat your oven to 180°C (355°F). Line the bottom of your 8-inch round cake pan with parchment paper and grease the sides with a light coating of oil or vegan butter. Don't skip the parchment on the bottom the blueberries in the batter can stick and tear the cake when you try to remove it from the pan.
Step 2 - Combine the Dry Ingredients
Add the flour, sugar, baking powder, and salt to your large mixing bowl. Whisk together thoroughly until there are no lumps and the baking powder is evenly distributed. Uneven baking powder creates spots in the cake that taste metallic thorough mixing at this stage prevents it entirely.
Step 3 -Add the Wet Ingredients
Pour the dairy-free milk, oil, lemon juice, lemon zest, and vanilla extract into the dry ingredients. Mix until just before fully combined the batter will look thick and slightly rough at first, then loosen up as you continue mixing for another minute. Stop mixing when you no longer see dry flour streaks. Don't overmix. Overmixing develops gluten and produces a dense, tough cake rather than a tender, airy one.
Step 4 - Fold in Half the Blueberries
Add half of the blueberries (about ⅔ cup) to the batter and fold them in gently using your rubber spatula. Two or three gentle folds is all you need you want the berries distributed through the batter, not mashed into it. A few streaks of batter color from the blueberries is completely fine.
Step 5 -Fill the Pan and Top with Remaining Blueberries
Pour the batter into your prepared cake pan and spread it into an even layer. Scatter the remaining blueberries across the top, then gently press some of them into the surface with your fingertip about halfway into the batter. This keeps them anchored during baking so they don't roll off the top when the cake rises.
Step 6 - Bake
Place the cake on the middle rack of your preheated oven and bake for 50 minutes to 1 hour. Check at the 50-minute mark by inserting a toothpick into the center if it comes out with wet batter, give it another 5–10 minutes. If it comes out clean or with a few moist crumbs (not wet batter), the cake is done. This is a moist cake by design a few crumbs on the toothpick is normal and correct.
Step 7 - Cool Properly
Let the cake cool in the pan for 10 minutes before turning it out onto a wire rack. This resting time lets the structure firm up so the cake doesn't crack or crumble on unmolding. Cool on the rack for at least 20–30 minutes before slicing cutting into a hot cake releases steam from the crumb and can make it gummy in the center.