Ingredients:
- Cupcakes:
- 1/2 cup granulated sugar
- 1/2 cup packed brown sugar
- 6 tablespoons butter, softened
- 3 large eggs
- 1 teaspoon vanilla extract
- 8 ounces cake flour (about 2 cups)
- 1/2 teaspoon baking soda
- 1/4 teaspoon salt
- 1/4 teaspoon ground cinnamon
- 1/2 cup buttermilk
- 1/3 cup plus 2 tablespoons walnuts, toasted, chopped, and divided
- Frosting:
- 1/2 teaspoon cream of tartar
- 3 large egg whites
- 3/4 cup maple sugar or granulated sugar
- 1/4 cup water
- Dash of salt