Preheat the oven to 350°F (175°C).
Grease and flour two round cake pans.
In a large bowl, cream together the butter and sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition.
Stir in the vanilla extract.
In a separate bowl, combine the flour and baking powder.
Gradually mix the dry ingredients into the wet mixture, alternating with the milk.
Divide the batter into two bowls; color one pink and leave the other plain.
Pour the batters into the prepared pans and bake for 30-35 minutes.
Let the cakes cool completely before frosting.
Frost with buttercream and decorate with sprinkles.