First is to make the sticky toffee topping. You will need a small saucepan and a 21cm cake tin (not springform).
Melt the 50g butter in the pan, and add the 50g sugar until it has dissolved and starts to boil. If you are using the red food colouring, add 1/2 a tube now. Pour this straight into the cake tin (make sure you have greased it) and spread evenly.
Peel, core and dice the apples into small chunks and arrange on top of the sticky toffee in the cake tin.
The next step is making the sponge. Soak the raisins in the calvados overnight, or if you don't have time microwave the calvados and raisins together for 1 minute.
Cream the brown sugar and butter well with a whisk, then mix the eggs and vanilla in.
Add the flour (both types), cinnamon, and baking powder and mix well until smooth.
Drain the raisins and add to the cake mix.
Pour the cake mix over the toffee apple mix in the cake tin, and bake on 170' for 30-40 minutes until a skewer comes out clean.
Allow to cool for 15 minutes or so, then turn out carefully onto a cake stand or plate.
Finally if you want to serve with extra toffee sauce (optional). Heat the butter, calvados and sugar in a saucepan until dissolved and starting to bubble. Remove from the heat and add the cream and food colouring.
Serve immediately.