Preheat oven to 170ºC/150ºC Fan/325ºF/Gas mark 3

Chop the butter and marzipan to make them easier to break down, and put them in the bowl of the food processor, fitted with the double-bladed knife, with the sugar

Process until combined and pretty well smooth

Add the almond essence and vanilla extract. Process again

Break the eggs one at a time through the funnel, processing again each time

Tip the flour down the funnel, processing yet again, and then pour the mixture into the prepared tin, scraping the sides and bottom with a rubber spatula

Bake for 50 minutes, but check from 40

When the cake looks golden and cooked and a skewer comes out cleanish, remove from the oven and leave to cool in the tin before turning out