Step 1: Preheat the oven

• Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans or line them with parchment paper.

Step 2: Mix the dry ingredients

• In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.

Step 3: Cream the butter and sugar

• In a large mixing bowl, beat the softened butter and granulated sugar with an electric mixer on medium speed until light and fluffy, about 3–4 minutes.

Step 4: Add egg whites and vanilla

• Gradually add the egg whites, one at a time, beating well after each addition. Stir in the vanilla extract.

Step 5: Incorporate dry ingredients and milk

• Alternate adding the dry ingredients and milk to the butter mixture, beginning and ending with the dry ingredients. Mix on low speed until just combined. Do not overmix.

Step 6: Pour into pans

• Divide the batter evenly between the prepared cake pans. Smooth the tops with a spatula.

Step 7: Bake the cake

• Bake for 25–30 minutes, or until a toothpick inserted into the center comes out clean.
• Let the cakes cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.

Step 8: Make the frosting (optional)

• Beat the softened butter with an electric mixer until creamy. Gradually add the powdered sugar, vanilla extract, and heavy cream. Beat until the frosting is smooth and fluffy.

Step 9: Assemble the cake

• Place one cake layer on a serving plate and spread a layer of frosting on top. Add the second layer and frost the top and sides. Decorate as desired.

Step 10: Serve and enjoy

• Slice the cake and serve at room temperature for the best flavor and texture.