To test if cheesecake is cooked, give the pan a gentle shake. The centre should have a slight wobble. Cheesecake can be made up to two days ahead. Refrigerate covered. Reheat remaining chocolate sauce before serving.
250g packet Choc Ripple biscuits
75g unsalted butter, melted
75g dark chocolate, chopped
1⁄4 cup pure cream
500g cream cheese, chopped, at room temperature
2/3 cup caster sugar
2 tblsps cocoa powder, sifted
2 eggs, at room temperature
125g dark chocolate, melted, cooled
250g tub sour cream
3 tsps powdered gelatine
1⁄2 cup water
3⁄4 cup caster sugar
1/3 cup raspberry jam
Invert the base of a 22cm round springform pan. Grease and line base and side with baking paper. Place on oven tray.
2 Process biscuits in a food processor until finely crushed. Add the butter and process until combined. Press evenly over the base and three-quarters of way up the side of pan. Refrigerate while preparing filling.
3 To make filling, process cheese, sugar and cocoa in same, clean food processor until smooth. Add eggs, one at a time, processing until combined. Add chocolate and sour cream. Process until smooth. Pour into prepared pan and smooth over the top.
4 Cook in a moderately slow oven (160C) for 50 minutes, or until just set. Turn off oven. Cool in oven with door ajar for 1 hour. Remove. Refrigerate, covered, overnight.
5 To make topping, sprinkle gelatine over half the water in a heatproof jug. Sit jug in a saucepan of simmering water. Stir until gelatine is dissolved. Remove from pan.
6 Place sugar and remaining water in large bowl of an electric mixer. Beat on high for 4 minutes. With motor operating, gradually add gelatine mixture in a thin, steady stream. Beat for a further 6 minutes, or until thick and fluffy.
7 Stir jam until smooth. Fold through topping. Immediately spoon over cheesecake.
8 Place chocolate and cream in a heatproof bowl sitting over a saucepan of simmering water. Stir until melted. Remove.
9 Drizzle some of the melted chocolate over the cheesecake. Serve with remaining.