Yields: 24 cupcakes
3 cups all purpose flour
1 teaspoon baking soda
1/2 teaspoon baking powder
1 teaspoon salt
2 teaspoons ground cinnamon
1/2 teaspoon freshly grated nutmeg
1/4 teaspoon ground cloves
1 cup vegetable oil
2 large eggs, room temperature
1 tablespoon pure vanilla extract
3/4 teaspoon grated lemon zest
2 cups packed light brown sugar
3 cups packed grated zucchini
1 cup walnuts (about 3 ounces), toasted and coarsely chopped
Preheat oven to 350 degrees. Line standard muffin tins with paper liners. Whisk together flour, baking soda, baking powder, salt, cinnamon, nutmeg, and cloves. In another bowl, whisk together oil, eggs, vanilla, and zest until well blended; whisk in brown sugar until smooth. Stir in zucchini, then add flour mixture and stir until just combined. Stir in walnuts.
Divide batter evenly among lined cups, filling each three quarters full. Bake, rotating tins halfway through, until a cake tester inserted in centers comes out clean, about 20 minutes. Transfer tins to wire racks to cool completely before removing cupcakes. Cupcakes can be stored overnight at room temperature or frozen up to 2 months, in airtight containers.
To finish, use an offset spatula to spread cupcakes with frosting. Refrigerate up to 3 days in airtight containers; bring to room temperature before serving.