Toast the nuts in a pan over a medium heat. Add the sugar, continue toasting, shaking the pan occasionally until all the sugar has dissolved. Remove the pan from the heat. Immediately spread the nuts onto a sheet of baking paper, leave to cool. Roughly chop the nuts.
Boil the sugar, water and lemon juice in a pan without stirring. Reduce the heat and simmer, swirling the pan occasionally until a light brown caramel has formed. Remove the pan from the heat, pour in the cream, continue to simmer and stir over a low heat for approx. 10 mins. until the caramel has dissolved. Remove the pan from the heat, let the caramel cool.
Finely crush the biscuits in a plastic bag using a rolling pin or blitz them in a food processor, mix with the butter and half of the nuts. Spread the mixture over the bottom of the prepared tin and press down firmly with the base of a glass.
Cream cheese mixture
Using the whisk on a hand mixer, thoroughly combine the cream cheese, half the caramel sauce and all the remaining ingredients. Spread the mixture over the biscuit base.
For approx. 40 mins. in the centre of an oven preheated to 180°C. Remove from the oven, allow to cool slightly, remove the tin frame, slide the cheesecake onto a plate and leave to cool. Top with the remaining caramel sauce and nuts.