Combine the crushed digestive biscuits with the melted butter. Mix until the crumbs are well coated.

Press the mixture firmly into the bottom of a springform pan to form a compact base. Chill in the refrigerator while you prepare the caramel.

In a medium saucepan, combine the sweetened condensed milk, butter, and brown sugar. Cook over medium heat, stirring continuously until the mixture thickens and becomes a golden caramel color, about 5-10 minutes.

Pour the caramel over the chilled biscuit base and return to the refrigerator to set, at least 30 minutes.

In a large bowl, beat the cream cheese until smooth. Add powdered sugar and vanilla extract, and beat until well combined.

Gently fold in the whipped cream until the mixture is smooth.

Spoon the cheesecake filling over the caramel layer, smoothing the top with a spatula. Chill in the refrigerator for at least 2 hours, or until set.

Place the chocolate chips in a heatproof bowl.

Heat the heavy cream in a small saucepan until it just begins to boil. Pour the hot cream over the chocolate chips and let sit for 1-2 minutes. Stir until the chocolate is completely melted and the mixture is smooth.

Allow the chocolate to cool slightly, then pour over the set cheesecake filling. Return to the refrigerator and chill until the chocolate is firm.

Once fully set, remove the cheesecake from the springform pan. Slice and serve chilled.