Preheat oven to 350°F/177°C. Cover the removable bottom and base of a 10’ spring form pan with aluminum foil. Set aside.
Prepare butterscotch according to package instructions. Pour brownie batter in the prepared pan and level out with an offset spatula. Bake for 20-25 minutes or until set. Set aside. This will serve as your crust.
In a mixer bowl with the paddle attachment, beat together cream cheese and sugar until smooth. Add eggs one at a time. Once fully incorporated, fold in cornstarch and cream, then stir until well combined.
Pour cream cheese mixture into baked butterscotch crust. Bake in a preheated oven at 275°F/153°C. Place pan in a baine marie and fill with boiling water up to 1 inch of the pan. Bake for 1-2 hours or until cheesecake is set.
While cheesecake is baking, prepare the caramel sauce. In a saucepan, caramelize brown sugar. Add in the cream and stir until smooth, then add in the butter and vanilla. Set aside to cool.
Once the cheesecake is set, garnish with pecans or any nuts of your choice as the border, then pour an ample amount of caramel sauce to cover the middle of the cheesecake. Refrigerate to set.
Cut when cool.