Salted butterscotch popcorn cheesecake

To make the popcorn, put a large pot with a lid over a medium-high heat, and add the oil and salt. Drop in a couple of popcorn kernels and cover the pan with a lid. When the kernels start to pop, add the rest of the corn and cover with the lid. Shake the pan to coat the kernels evenly and leave to heat up. When they start popping, shake the pan around gently to make sure the unpopped kernels get to the heat and the popped ones don’t burn at the bottom of the pan. (Set the lid slightly ajar to release some of the steam, to make the popcorn crisper.) Once the popcorn has stopped popping every few seconds, take it off the heat and leave it to one side until all the popping has stopped completely.

Butter a 20cm springform cake tin, and line the base and sides with greaseproof paper. To make the cheesecake base, put the biscuits in a sealed food bag and smash them with a rolling pin into crumbs, or put them in a food processor and grind to coarse crumbs. Tip into a mixing bowl, and stir in a small handful of popcorn and a pinch of sea salt. Melt the butter in a saucepan over a low heat and pour it over the crumbs. Mix it all together with a fork and tip it into the cake tin. Tap the side of the tin with the flat of your hand to even the crumb mix out, and gently compress it with the back of a large spoon until it’s packed in and level. You want it fairly well packed so that it holds together. Put in the fridge to cool.

To make the sauce, heat the butter, milk, cream, sugar and salt together in a medium non-stick pan, and, stirring continuously, bring to the boil. (Although it may look super-tempting, don’t swipe your finger over the spoon: caramel can give a nasty burn.) Turn down to a simmer and cook for 10 minutes, stirring occasionally. Remove from the heat and set to one side. If, when it’s cooler, the mixture is stiff, warm it up over the heat with a splash of milk to loosen it; you want it still warm and runny so that you can pour it over the cheesecake.

To make the cheesecake filling, put the mascarpone, quark or yogurt and icing sugar intoa mixing bowl or the bowl of a stand mixer, andbeat it together. (If you don’t have a stand mixer,use an electric hand whisk.) Mix until wellcombined and thickening, then add the creamand continue to mix. You want it thick, butnot over-whipped. Pour in half the saltedbutterscotch sauce, and fold it through the creamcheese mixture to create a ripple effect. Taste itand add more sauce or salt if you feel it needs it.

Pile the mixture on top of the buttery biscuit base and smooth it down with the back of the spoon or a palette knife. Cover with clingfilm and chill for at least 2 hours or until it is set. Remove from the tin, then scatter the rest of the popcorn over the top, drizzle with the remaining butterscotch sauce and serve.