1.Pre-heat the oven to 200/Fan 180 / Gas mark 6
2.Grease a pudding basin or a cake tin plus 3 extra baking trays.
3.Sift together the flour and baking powder into a large bowl.
4.Add the butter, eggs and sugar and whisk thoroughly. The consistency should be to dropping off the spoon. If it is too dry, add a little milk.
5.Divide the mixture into 4 bowls (if using 3 colours, or 3 bowls if using 2 colours etc) – one of the bowls should contain double the mixture of the other 3.
6.To the largest portion, add the vanilla and stir.
7.Add the flavouring and food colouring to the remaining bowls, a little at a time until the desired shade is achieved.
8.Pour the coloured mixture onto the greased baking trays and bake for 8-10 mins. Remove and leave to cool.
9.Cut hearts from the coloured sponge using a heart cookie cutter.
10.Stack the hearts on top of each other in the pudding basin, if using, or arrange the hearts on the bottom of the cake tin.
11.Pour the remaining vanilla batter over the hearts until they are hidden.
12.Bake for about 15min or until an inserted skewer comes out clean.
13.Leave to cool and then invert onto a plate – your heart is revealed and as you cut into the cake, more coloured hearts will be found!