About this recipe:We made some buns for my daugher's birthday so she and her friends could decorate them. I used the sponge cake rule which basically involves weighing the eggs and then measuring equal measures of butter, sugar and flour. That's why there are no measures in the recipe below - it totally depends on what your eggs weigh. If you want to make chocolate buns, replace 30g of the flour with 30g cocoa powder.
Preheat the oven to 180 C / Gas 4. Line 2 12-hole bun trays with paper muffin cases.
Weigh the eggs whole (shell included) and make a mental note of their weight. Weigh out the same amount of butter and place in a large mixing bowl. Using a stand mixer, electric beater or a wooden spoon, beat the butter until it is fluffy, about 5 minutes.
Weigh out the exact same amount of caster sugar; add it in batches to the butter, mixing it well each time. Continue to beat for a few minutes or until the mixture is light and airy. Add one egg and beat well to blend it in. Repeat with each egg. Stir in the vanilla if using.
Weigh out the exact same amount of self-raising flour (or replace 30g of it with cocoa powder if you are making chocolate fairy cakes). Add pinch of salt. Add a third of the flour at a time (and cocoa powder, if using) and fold in gently with a spatula. The mixture should be light and drop of the spatula easily. If it's too stiff, you can add 1 or 2 tablespoons of milk. Spoon the mixture into the muffin cases, about halfway full.
Bake for 10-15 minutes, depending on their size. You can test them by placing a skewer or knife into the centre - if it comes out clean, they are ready.
Remove onto a wire rack and leave to cool while you make the icing: Put the chocolate and butter in a bowl and place on top of a saucepan of very hot water. Stir until it has completly melted. Use to ice the fairy cakes. Decorate with hundreds and thousands, Smarties or jellybeans.
Use the same rule for making a sponge cake in 2 (greased and lined) 20cm sandwich cake tins. The icing can be used to sandwich them together.