For the crumble topping:

• 140g (1 cup) flour
• 80g (½ cup) instant oats
• 115g (½ cup) brown sugar
• 115g (½ cup) salted butter, melted

For the biscuit base:

• 200g Tennis biscuits (or plain vanilla biscuits)
• 30ml (2 tbsp) brown sugar
• 2.5ml (½ tsp) cinnamon
• 100g (7 tbsp) salted butter, melted

For the cheesecake layer:

• 500g (525ml) full fat cream cheese, softened
• 125ml (½ cup) white sugar
• 45ml (3 tbsp) sour cream
• 5ml (1 tsp) vanilla extract
• 2 large eggs
• 2 large Granny Smith apples
• 2.5ml (½ tsp) mixed spice
• 5ml (1 tsp) cinnamon

For the salted caramel sauce:

• 300g (1½ cups) white sugar
• 125ml (½ cup) water
• 175ml (⅔ cup) cream
• 50g (55ml) unsalted butter
• 5ml (1 tsp) vanilla extract
• 5ml (1 tsp) salt

1.) Preheat the oven to 180ºC and grease a 23cm springform tin.

2.) To make the crumble place the flour, oats and brown sugar in a small bowl. Pour in the butter and mix well until evenly combined. Place in the fridge until needed.

3.) Next, make the biscuit layer. Place the biscuits, brown sugar and cinnamon in a food processor and blitz into fine crumbs. Add the butter and blitz again to combine. Tip the mixture into the tin, press down into the base and refrigerate while you make the filling.

4.) To make the cheesecake layer place the cream cheese in a bowl and beat until smooth. Add the sugar, sour cream and vanilla and beat well. Add the eggs one at a time and beat until smooth. Pour the mixture over the base and smooth with a spatula.

5.) Working quickly, peel the apples and slice thinly. Arrange the slices over the cheesecake filling to cover it completely. Sprinkle the mixed spice and cinnamon over the apples, then add the crumble topping.

6.) Bake the cheesecake for 50 minutes. Remove from the oven and leave to cool to room temperature. Refrigerate for 6 hours or overnight.

7.) For the salted caramel sauce place the sugar and water in a heavy-bottomed saucepan. Cook over a low heat without stirring until the sugar dissolves. Use a pastry brush dipped in water to wash down any sugar crystals that collect on the sides of the saucepan to prevent the sauce from crystallising.

8.) Increase the heat and continue to cook until the syrup turns golden (about 174ºC). Remove the saucepan from the heat and whisk in the cream, taking care as the mixture will bubble up and produce lots of hot steam! Return the pot to the heat for another minute or two, stirring continuously until smooth. Remove from the heat and whisk in the butter, vanilla and salt. Allow to cool for 10 minutes before serving.