Chocolate, nut and caramel shortbread tart

Preheat oven to 190°C. Process biscuits in a food processor until fine crumbs form. With motor running, add egg and process until mixture is evenly damp. Using your hands and the base of a glass, press crumb mixture evenly and firmly over base and sides of a greased 26cm round loose-based fluted tart tin. Bake in oven for 12-14 minutes or until tart case is dry. Set aside to cool.

Place sugar, 150ml of cream, butter and vanilla in a saucepan. Stir over medium heat until combined, then simmer for 8 minutes. Stir in nuts, then spoon into tart case. Set aside to cool.

Place remaining cream in a small saucepan and bring almost to the boil over medium heat. Remove from heat, add chocolate, and stir until chocolate melts and mixture us smooth and combined. Spoon over caramel layer in tart case, level with a spatula, then refrigerate for 2 hours until set. Dust tart with cocoa and cut into then slices to serve. This tart will keep in the refrigerator for up to 3 days.