Cream butter and sugar until light and fluffy.
Beat in eggs and add flour.
Split mixture in two and add cinnamon to one half, and cocoa or food colouring to the other. Mix in well.
Mix halves together but only roughly, allowing the two colours to form stripes but not blend.
Fill baking trays with paper cupcake cases and put approximately two tsp of mix in each.
Bake at 190C (375F) for about 15 minutes until cakes are risen and firm.
Remove from oven and leave to cool.