Prep Time: 20 minutes | Cooking Time: 30 minutes | Total Time: 50 minutes
Kcal: 310 kcal | Servings: 12 servings

Ingredients:

• 2 3/4 cups all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 3/4 cup unsalted butter, softened
• 1 3/4 cups sugar
• 5 large egg whites, at room temperature
• 2 teaspoons vanilla extract
• 1 cup buttermilk, at room temperature
• 1/3 cup sour cream, at room temperature

Directions:

1. Preheat oven to 350°F (175°C).
2. Grease and flour two 9-inch round cake pans.
3. In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
4. In a large bowl, beat butter and sugar until light and fluffy.
5. Add egg whites and vanilla, beating well after each addition.
6. Alternately add flour mixture and buttermilk to the butter mixture, beginning and ending with flour.
7. Stir in sour cream.
8. Divide batter evenly between prepared pans and smooth tops.
9. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
10. Cool cakes in pans for 10 minutes, then remove to wire racks to cool completely.