Sponge: Melt 100g dark chocolate with 175g margarine. Add to all this in a bowl and whisk together: 75g sugar; 3 eggs; 150g self raising flour; 1 tsp baking power; pinch salt; 1 tsp vanilla; 2 tsp cinnamon; 1tsp ginger; 1/2 tsp nutmeg (spices not all necessary, as long as you have at least one).Pour into greased baking tray of appropriate depth (sponge will rise to about double in height) and bake at gas mark 5 until springy to touch in middle. Cool lying upside down on a cooling rack to flatten the top a bit.
Decoration: When cooking make up small amounts of green and red icing from pre-made cake icing. Make the red bits into small balls (holly berries) and roll the green then cut out holly leaf shapes (i have a cutter this shape)
Fudge: Make the fudge by melting a bag of toffees with 200ml evaporated milk and 2tsp cinnamon until sticky and spread on the top of the cake.
Icing: Roll out the white icing and cover the cake, carefully trimming it to stop on the edges of the top.
Presentation: Cut the icing only into slices (see picture) and decorate with holly leaves and berries, using a touch of water on the white icing to stick them down.