Ingredients: 225g butter, softened; 325g caster sugar; 2 eggs; 1tsp vanilla extract; 225g plain flour; 75g cocoa powder; 1tsp bicarbonate of soda; ¼tsp salt; 175g dark chocolate 55-70% cocoa solids, chopped into small pieces or chocolate chips.
For the cheesecake: 15g cocoa powder, sifted; 25ml strong coffee, such as espresso; 1tsp vanilla extract; 500g mascarpone; 400ml double or regular cream; 50g icing sugar; 50g dark chocolate 55-75% cocoa solids, grated, for sprinkling; 9-12 of the cookies you made previously.
1. Make the cookies first. Preheat the oven to 180C/160C fan/gas 4.
2. Place the butter in a large bowl and beat until very soft. Add the sugar and beat until the mixture’s pale and fluffy. Crack in one egg at a time then add the vanilla extract.
3. Sift in the flour, cocoa powder, bicarbonate of soda and salt, then add the chocolate pieces or chips.
4. Form the dough into balls, then arrange on the baking sheets, placing six to seven balls of on each, leaving space for the cookies to spread.
5. Bake for 10-14 minutes, or until the cookies look slightly cracked on top. You’ll need to cook in three batches.Take out of the oven and allow to cool for a few minutes.
6. To make the cheesecake whisk together the cocoa powder, coffee, vanilla extract, mascarpone, cream and icing sugar until thick.
7. Arrange somecookies in the bottom of a 23cm-diameter cake tin, then spread over one-third of the chocolate cream mixture. Add a second layer of cookies, then another layer of chocolate cream, followed by a final layer of cookies and a final layer of chocolate cream.
8. Use a spatula to smooth the top layer, then cover the tin with cling film and place in the fridge to chill for eight hours or, even better, overnight.
9. To remove from the tin, run a small, sharp knife around the cheesecake to loosen the edges.