Frozen chocolate and hazelnut cheesecake

Line a 900g loaf tin with clingfilm (oiling the tin lightly first helps it to stick). Put the soft cheese, vanilla, egg yolks from the separated eggs, Nutella and 50g of the sugar in a mixing bowl and whisk using electric beaters until smooth. Clean the whisks and, in another bowl, beat the egg whites until stiff. Add the remaining 50g of sugar, beat until glossy and thick, and then fold into the soft-cheese mixture. Finally, whisk the whipping cream until thick, then fold this in, too.

Tip the hazelnuts into the base of the tin and spread evenly. Scrape the cheesecake filling on top, spread to flatten the top, then freeze for 3 hours until almost solid.

Crush the bourbon biscuits in a bowl with the end of a rolling pin to rough crumbs, then mix with the melted butter. When the filling is ready, scatter the biscuit base over, press to compact on the frozen cheesecake, and freeze again overnight.

To serve, remove the cheesecake from the freezer 15 minutes before you want to serve it, and invert carefully onto a serving plate, peeling away the clingfilm. Slice and serve with single cream, if you like.