Lightly grease the base of a 20cm springform tin.|
Finely crush the biscuits in a food processor for 30 seconds, or put then in a plastic bag and roll with a rolling pin. Transfer to a bowl and add the mixed spice and butter. Stir until all the crumbs are moistened, then spoon the mixture into the tin and press it firmly into the base and side. Refridgerate for 20 minutes, or until firm.
Preheat the oven to 180°C (350°F). Beat the cream cheese until smooth. Add the sugar and beat until smooth. Add the eggs, one at a time, beating well after each addition. Mix in the vanilla, orange juice and zest.
Pour the mixture into the crumb case and bake for 45 minutes, or until just firm. To make the topping, combine the sour cream, vanilla, orange juice and sugar in a bowl. Spread over the hot cheesecake, sprinkle with nutmeg and return to the oven for 7 minutes. Cool, then refrigerate until firm.