Preheat the oven to 400° F/ 200° C /Gas 6.

In a large baking bowl beat together the butter and sugar until light and creamy. Slowly add the eggs, continuing to beat with the butter and sugar mix; resist the temptation to add the eggs too fast to avoid curdling the cake.

Add the vanilla extract and stir.

Sieve the flour into the baking bowl and again, continue beating until smooth. Place half of the mixture in another bowl, add the food coloring a little at a time until you have a color you like. Stir well.

Grease a 6"/15cm square cake tin and divide into 2 by placing a thick layer of aluminum foil down the center. Put the pink mixture into one side and the plain cake the other.

Place in the oven for 25-30 minutes, or until the cake springs back when pressed lightly. Remove from the oven and leave to cool on a wire rack.

Cut each cake to the same size, then cut each cake in half lengthways. Take a pink cake and brush one side with the warmed jam. Place a yellow piece next to it, jam side together and push gently together.

Brush the top surface with jam and place a piece of yellow cake atop a pink piece and vice versa. Brush all the outside edges with more jam.

Brush the rolled marzipan with a little jam and wrap it all around the cake., hiding the seam underneath. Trim away any excess. Chill in the refrigerator for at least an hour, then serve.