These deliciously balanced no-bake chocolate cheesecake bars make for the perfect afternoon pick-me-up with tea, or dressed with fresh berries for dessert.
1. Lightly butter a deep 23cm square cake tin and line with baking paper, ensuring that it comes up and over the sides of the tin, and put it in the fridge.
2. Reserve two of the dark chocolate digestives, then put the rest of the biscuits into a food processor and blitz until fine. Add the oats, melted butter and 1 tbsp of Nutella, then blitz again until it comes together. Tip the crumbs into the chilled tin, spreading them evenly and into all corners, before compacting flat with the base of a glass. Chill for at least 30 minutes.
3. Use an electric whisk to beat together the soft cheeses and icing sugar. When all the sugar has been incorporated, add the melted chocolate, remaining Nutella and 2 tbsp of milk, and beat until fully combined. If the mixture looks a little thick add the extra 1 tbsp of milk. Spoon the filling onto the chilled biscuit base and spread level with a spatula. Crush the last two digestives to crumbs, mix with the chopped hazelnuts and sprinkle evenly across the top of the cheesecake. Chill for at least 4 hours or preferably overnight.
4. When completely chilled, release one side of the cheesecake by gently pulling up one length of the baking paper. Holding the paper firmly, angle the tin and pull to slide the base of the cheesecake flat onto a chopping board. Use a sharp knife to cut into slices or squares. This will keep, chilled, for up to a week.