Make sure the eggs and milk are at room temperature, otherwise the cake mixture may curdle!
Cream the butter, vanilla and sugar together until light and fluffy.
Beat in eggs, one at a time until light and creamy.
Mix in the flour and milk, in two batches until combined. Do not over mix!
Bake at 180C for 12 minutes.
For the icing, beat the butter with the milk and 1 cup of the icing sugar. Add the rest of the icing sugar gradually. At this stage you can either add a few drops (just A FEW!) of food coloring or about 3 tbs of cocoa for chocolate frosting.
Make sure the cupcakes are completely cold before icing!