Salted Caramel Cheesecake

Steps

1. 1
   Make the salted caramel: melt the sugar over medium-high heat in 4 batches, stirring in the next batch once the previous one is liquefied. Once all melted and amber-coloured, remove from heat. Stir in the cold butter and salt, then whisk in the cream in two additions (it will steam). Return to medium-high heat and boil for 1 minute while stirring. Pour into a bowl, press cling wrap directly onto the surface, and cool for 1 hour.
2. 2
   Make the base: blitz the biscuits into crumbs and mix with cinnamon, brown sugar, melted butter, and salt. Grease and line a 23×33cm pan with overhang, press the crumb mixture into the bottom, and refrigerate.
3. 3
   Make the filling: beat the cream cheese until smooth, then mix in sour cream, sugar, salt, and vanilla extract. Add eggs one at a time, beating well after each addition. Pour onto the base. Dollop half the caramel randomly across the surface and swirl gently (you'll decorate with more caramel later). Bake at 160°C for 35 minutes. Cool in the oven for 1 hour with the door open about 8cm.
4. 4
   Fill the cracks and chill: some cracks may form in the swirls as it cools—fill these with caramel. Drizzle most of the remaining caramel over the surface and refrigerate for at least 6 hours. Lift out using the paper overhang (warm the base gently if needed to melt the butter), sprinkle with sea salt flakes, cut into portions, and serve.
5. 5
   Substitutions: use any plain biscuits (Marie, Graham, or digestive) instead of Biscoff, but double the cinnamon. The caramel can be made ahead and kept refrigerated for up to 2 weeks, but warm it to room temperature before using (it becomes too thick when cold).