To make a simple buttercream icing for piping you will need:

Unsalted butter - this makes the icing creamier
Icing sugar

When making icing I do not use any measurements but start with a suitable heap of icing sugar in a bowl and add cold water, a few drops at a time. It is easy to add more water or more icing sugar. The icing needs to be mixed into a stiff paste which will hold its shape when being piped. Whip in desired amount of unsalted butter to the icing (I roughly use a 50:50 butter to icing quantity) and again, add more icing sugar to get the icing back to the right consistency. When you lift the spoon up the icing should break and form a stiff peak.

This buttercream can be smoothed or piped onto cakes using a piping bag or nozzle.

To make chocolate cupcakes you can easily adapt the below sponge recipe; reduce the amount of flour to 80-85g and top the amount up to 100g using 100% cocoa powder. (100% is best as it gives a stronger and richer chocolate taste)

I decorated these cupcakes with chocolate butter icing; I just added cocoa powder to the icing mixture. I have used white chocolate chips, dark chocolate hearts, pearl sugar balls and honeycomb pieces to decorate the icing.

I think this recipe is the fastest and tastiest recipe for a victoria sponge. It is an all in one recipe which means throwing all of the following ingredients into a bowl and mixing them until white and creamy.

100g self-raising flour
100g caster sugar
100g butter
2 medium eggs
1 teaspoon vanilla essence
1/2 teaspoon baking powder

Pour into cupcake cases or a tin lined with grease proof paper.
Bake in an oven at 175C (fan) / 180C for approximately 20 minutes. Times can be adjusted and reduced for cupcakes.

Tips for making your sponge rise:
1) Blend the ingredients well - this will add enough air to the mixture for it to rise
2) When putting the mixture into the cases or tin do not spread or flatten it - this will push the air bubbles out
3) Resist all temptation to open the oven during cooking! This will cause the sponge to sink and cannot be reversed. Leave the sponge to bake for a suitable amount of time (15 minutes min) and only open the door towards the very end of cooking.