Preheat the oven to 350°F (175°C).

Crush the digestive biscuits or graham crackers and mix with melted butter. Press into the base of a springform pan and bake for 10 minutes.

In a mixing bowl, combine cream cheese and granulated sugar. Beat until smooth, then add eggs one at a time, mixing gently. Add vanilla extract.

Pour the cheesecake filling over the cooled crust and bake for 45 minutes. The edges should be set, and the center should jiggle slightly.

Cool completely, then cover and refrigerate for at least 4 hours.

In a saucepan, combine sweetened condensed milk, brown sugar, and butter. Cook over medium heat, stirring continuously for about 10 minutes until thickened.

Spread the caramel over the chilled cheesecake and let it set in the fridge for about an hour before serving.