- 3 small red plums
- 1¾ cups hazelnut meal or almond flour
- ¾ cup oat flour
- 2 teaspoons baking powder
- ½ teaspoon kosher salt
- ½ teaspoon ground cinnamon
- ¼ teaspoon baking soda
- 2 large eggs, separated
- ½ cup packed light brown sugar
- 2 teaspoons pure vanilla extract
- ½ cup buttermilk
- 1 tablespoon granulated sugar, for sprinkling
- Preheat oven to 400°F. Line a standard 12-cup muffin pan with paper liners.
- Halve and pit the plums. Thinly slice 2 plums for garnish. (You’ll need 2 or 3 slices for each muffin.) Cut the remaining plums into a small dice (about ½ cup).
- In a medium bowl, whisk together the hazelnut meal, oat flour, baking powder, salt, cinnamon and baking soda.
- In a large bowl, whisk together the egg yolks, brown sugar, vanilla, and buttermilk. Stir in the flour mixture. Fold in the diced plum.
- In a medium bowl, with a clean whisk, beat the egg whites until stiff peaks form, about 2 minutes. Stir ⅓ of the egg whites into the batter, then carefully fold in the remainder.
- Divide the batter evenly between the muffin cups. Top each cup with a few slices of plum and sprinkle with granulated sugar. Transfer the pan to the oven and immediately reduce the temperature to 350°. Bake until the muffins spring back when pressed gently, 18 to 22 minutes. Let muffins cool in the pan for 5 minutes then transfer them to a rack to cool completely.