I topped the birthday cupcakes with buttercream icing. I usually make my own mixture of milk and icing sugar, but it wasn't ever that yummy. This icing is scrumptious - it should be a dessert on its own!
Vanilla Buttercream Icing
3 cups icing sugar (confectioners/powdered sugar)
1 cup butter
1 tsp. vanilla
2 tbsp. whipping cream
beat the sugar and softened butter for 4 minutes. add the vanilla and cream and beat for 1 minute