Prepare caramel sauce: Heat the cream until warm. In a non-stick pan, melt granulated sugar in batches over medium-high heat, stirring gently to caramelize without burning. When sugar is melted and caramelized to a golden color, carefully pour in the warm cream to stop cooking and dissolve the caramel. Stir continuously over low heat until smooth. Remove from heat as needed to control temperature. Add salt and vanilla extract, mix well, then transfer to a bowl, cover with cling film, and let cool completely.
Make the biscuit base: Pulse digestive biscuits in a food processor until fine crumbs form. Add melted butter and pulse again until mixture resembles wet sand. Press the mixture evenly into the base of a 25 cm tart pan with a removable base using the back of a glass or your hand. Place in the freezer for 2-3 minutes to set.
Prepare the cheesecake filling: In a mixer bowl, combine about 200 g of cooled caramel sauce, icing sugar, 200 g cream, and cream cheese. Beat until smooth and creamy, about 1 to 1.5 minutes, until the mixture thickens and leaves marks. Avoid overbeating.
Assemble and chill: Pour the cheesecake filling over the chilled biscuit base and spread evenly with a spatula. Refrigerate until firm, preferably several hours or overnight for best results.
Serve: Remove the cheesecake from the pan and place on a serving platter. Pour remaining caramel sauce over the top and decorate with fresh mint leaves. Cut into about 10 slices and serve.