Instructions:

1. Preheat oven to 350°F.
2. Prepare your cake pans with cake release spray, homemade cake release, or line the pans with parchment paper rounds.
3. Combine all dry ingredients (minus sugar) into a small bowl and set aside.
4. Combine the milk and vanilla in another small bowl and set aside.
5. Cream the butter in a large mixing bowl or the bowl of a stand mixer with a paddle attachment. Slowly add in the sugar until fully combined and fluffy.
6. Add in the egg whites one at a time, making sure to combine each before adding the next.
7. Add in about ½ of the dry mixture while mixing on a low speed. Alternate adding in dry and wet ingredients until they are all combined. Mix for an additional 3 minutes on a medium speed.
8. Distribute the batter evenly between your prepared pans (either three 6-inch pans or two 7-inch pans).
9. Bake for about 30-35 minutes or until a toothpick inserted comes out clean.
10. Let cool completely before frosting.

For the frosting:

1. Cream together the butter until light and fluffy and there are no lumps. Add in the powdered sugar one cup at a time while on a low speed.
2. Add in the vanilla and heavy cream and mix until light and fluffy. About 3-4 minutes.
3. To assemble the cake, place one layer of cake on a cake board or plate and top with about 1/2 cup of buttercream and smooth out evenly. Add the next layer and continue with each layer of cake. Completely cover the outside of the cake with the remaining buttercream and smooth with a bench scrapper or spatula. Personalize by adding toppings of your choosing!
4. Enjoy!