Beat butter and sugar till light and fluffy. Add eggs & yolks one at a time. Mix in vanilla extract gently.
Blend dry mix into the wet ingredients. Add milk, mix gently, avoid over-mixing.
Divide batter in pans, bake 25-30 mins. Cool in pans for 10 mins, then on rack.
Mix cocoa, sugar, butter, milk, vanilla. Ice cake when cool, add sprinkles. Enjoy!