• Preheat oven to 325 degrees F. Spray (3) 6 inch pans with nonstick spray and set them aside.
• In a large mixing bowl add flour, baking soda, baking powder and salt. Mix with a spoon to combine.
• In a small bowl mix milk and vanilla together.
• In a medium bowl mix softened (not melted) butter, vegetable oil, sugar, egg and egg white with hand mixer until mixture is fluffy and combined.
• Add small and medium bowls into large mixing bowl with the flour, mixing until smooth and no longer clumpy.
• Optional: If you want the cake to be colored inside, add a couple drops of food coloring into the batter and mix to combine until smooth.
• Pour batter into the 3 pans. With a spatula, gently smooth out the top.
• Bake for 20-22 minutes or until a toothpick comes out clean. Remove from oven and allow to cool completely before removing from pans and frosting.
• Once cakes are removed from pans, take a look at the top of each one. If they are not level, carefully trim rounded tops off cakes to level. This will make layering the cakes easier and look more clean. I do this with a sharp bread knife.
• Spread frosting on the top of each cake, completely covering it. Stack the cakes on top of each other. Spread frosting on the sides of the cake. Add rainbow sprinkles all over the top and sides of the cake. Serve and enjoy!

For the frosting:

• In a large bowl mix butter with hand mixer until fluffy. Add in confectioners sugar, continuing to mix until it's combined and creamy. Add vanilla and mix.
• Add in milk and continue to beat for 2 minutes until fluffy. If frosting seems stiff, add additional tablespoon of milk until it's a consistency you can spread.