Stage 1 - Toast the Pecans
Preheat your oven to 350°F (176°C) and arrange the raw pecans on a bare baking sheet in a single layer. Bake for 8–10 minutes, until they're fragrant and deep golden brown. Keep an eye on them in the last couple of minutes pecans go from perfectly toasted to burnt surprisingly fast. Remove from the oven and set aside to cool slightly.
Stage 2 - Prep the Salad While the Pecans Toast
While the pecans are in the oven, prep the rest of the salad: thinly slice the apples and red onion, then add them along with the arugula and dried cranberries (if using) to your large mixing bowl.
Stage 3 - Make the Dressing and Combine
In your mason jar or a small bowl, combine the lemon juice, maple syrup, salt, pepper, and olive oil. Whisk or shake vigorously until well combined and slightly emulsified. Taste and adjust more lemon for brightness, more maple if it needs sweetness, more salt if it tastes flat.
Add the toasted pecans to the salad and pour the dressing over everything. Toss to combine and serve immediately while the arugula is still crisp and the pecans are still warm from the oven.