1. Process biscuits until fine. Transfer biscuits to a medium bowl, stir in butter. Press mixture evenly over base and side of 20cm springform pan. Refrigerate while preparing filling.

2. Combine brown sugar, extra butter and 2 tablespoons of the cream in a small saucepan. Stir over medium heat, until sugar dissolves; simmer for 5 minutes.

3. Sprinkle gelatine over the water in a small heatproof jug; stand jug in a small saucepan of simmering water. Stir until dissolved.

4. Beat cream cheese and caster sugar in a medium bowl with an electric mixer until smooth. Beat remaining cream in a small bowl with electric mixer until soft peaks form. Stir slightly warm gelatine mixture into cream cheese mixture with the Mars Bars; fold in the whipped cream.

5. Pour 2 /3 of the cream cheese mixture onto the biscuit base in pan. Drizzle over 2 /3 of the butterscotch sauce. Swirl the mixture to distribute the butterscotch sauce. Repeat the process with remaining cream cheese mixture, butterscotch sauce.

6. Refrigerate for 3 hours or until set.

7. Meanwhile, combine chocolate and extra cream in a small saucepan; stir over low heat until smooth. Serve the cheesecake drizzled with milk chocolate sauce.

Suitable to freeze. Chocolate mixture suitable to microwave.