Easy Buttercream Frosting
Preheat oven to 350F and prepare two 8" cake pans with cake good or preferred pan spray
Whisk up eggs with oil, buttermilk, vinegar and melted butter and food coloring until combined and set aside.
Place dry ingredients into the bowl of your stand mixer and mix for a few seconds to combine
Add wet ingredients into your dry and mix on medium high for about a minute until combined
Pour into cake pans and bake for about 30 minutes or until a toothpick comes out cleanly. Cool and chill before frosting
Place egg whites and powdered sugar in a mixing bowl with the whisk attachment. Whisk to combine. Add in butter in small chunks then vanilla and salt. Whip on high until light and fluffy and white. Optional: switch to the paddle attachment and mix on low for 15-20 minutes until all air bubbles are gone.
Divide into 7 separate bowls and add your food coloring (yellow, orange, red, pink, purple, blue, green) Put the buttercream into a piping bag to fill your cake
Frost the outside of the cake as desired
Serving: 1serving | Calories: 1077kcal (54%) | Carbohydrates: 112g (37%) | Protein: 6g (12%) | Fat: 68g (105%) | Saturated Fat: 44g (220%) | Cholesterol: 188mg (63%) | Sodium: 409mg (17%) | Potassium: 74mg (2%) | Sugar: 92g (102%) | Vitamin A: 2035IU (41%) | Calcium: 44mg (4%) | Iron: 1.6mg (9%)