Mix butter,egg and castor sugar together,mix them well till fluffy and creamy add vanilla essence

In a separate bowl mix flour and baking powder and add to wet ingredients until the dough is well combined

Heat oven to 180 decrease and fill muffin pan with paper cups then spoon your dough and bake

Allow them to cool then for frosting mix all ingredients until creamy but not too yellow then use piping bag for decorating,then top with anything of your desire I just used choc chips