Preheat oven to 150C. Grease a 20cm (base measurement) springform pan. Line base and side with baking paper.
Process combined biscuit in a food processor until finely crushed. Add the butter. Process until combined. Spoon into pan and use a straight-sided glass to spread and press over the base and side. Place in fridge for 30 mins or until firm.
Process the cream cheese, sour cream and sugar in a clean food processor until smooth. Add the eggs, ginger and mixed spice. Process until smooth. Pour half the mixture into the pan. Drizzle with half the topping and swirl. Repeat with remaining cream cheese mixture and topping.
Place on a baking tray. Bake for 1 hour or until almost set. Turn oven off. Leave in oven, with door ajar, for 2 hours to cool. Place in fridge to chill. Drizzle with extra topping. Top with gingerbread men and candy canes.