Here's one I make all the time & it's very quick and easy...
8 oz (1 pack unsalted butter)
8 oz sugar
8 oz self raising flour to which add 1 level teaspoon of baking powder
4 large eggs, beaten
1 heaped tablespoon cocoa powder blended with just enough boiling water to make a 'loose' paste (consistency of double cream)
- pre heat oven to 170c.
- beat together butter and sugar with electric hand whisk (if butter not at room temp, blast in microwave for 30 secs)
- Add flour and eggs alternately in to butter and sugar mixture, mixing between each addition.
- Add cocoa mixture and beat again
- Divide mixture between two 8" greased and floured sponge cake tins. (use butter wrapper to grease and then dust each tin lightly with flour, tipping any excess flour away.)
- Put in oven for 25-30 mins. Do not open oven half way through to check! At the end of cooking time poke one of the cakes with a knife and if it comes out 'clean' then the sponges are cooked. Leave to cool for 5 minutes and then turn out and cool on wire rack.
- For a quick filling (if it's really too much trouble to make chocolate butter icing), get some Betty Crocker's chocolate fudge icing to spread inside the cake and on the top and then decorate with smarties/choc sprinkles to your heart's delight!