To make the caramel sauce, place the sugar, butter and cream into a saucepan and bring to the boil. Boil for about 5 mins while stirring. Set aside and let cool.
Pre heat the oven to 175C
To make the base. Place the cookies into a food processor and pulse until they for fine bread crumbs. Melt the butter in the microwave and then pour into the food processor, pulse a few more times and the pour into the prepared 25cm, lined cake tin. Press into the base.
To make the filling, place the cream cheese into a freestanding mixer bowl and beat until the mixture is smooth and in the ricotta and sugar and beat again. While still beating the mixture add the eggs in one at a time until combined. Pour half the mixture into the cake tin. then pour ⅛ of the caramel sauce onto the cake. Then pour over the remaining cream cheese mixture and drizzel with some more of the caramel sauce. Place into the oven and bake for 1 hour or until cooked.