Grease and line a 20cm X 20cm square baking tin and set aside.
Crush the biscuits until fine crumbs remain.
Add the melted butter and mix together well.
Press the biscuit base firmly into the prepared baking tin.
Whip the thickened cream and set aside.
Beat the softened cream cheese and caster sugar until smooth and creamy.
In a separate bowl, sprinkle the gelatine over the boiling water and stir until completely dissolved.
Beat the gelatine through the cream cheese mixture.
Beat through 150g of the salted caramel sauce (you may need to pop it in the microwave for a few seconds so that it is runny).
Fold through the whipped cream.
Pour the cream cheese mixture over the biscuit base.
Swirl the remaining warm salted caramel sauce through the top of the cheesecake (using a skewer or a knife).
Place into the fridge for 6 hours or until completely set.
Cut into slices and serve.