Throw the berries into a blender and puree as finely as possible. Pass it through a sieve to get rid of all the seeds, then put it in a sauce pan on a low flame. Add the sweetener, and allow the mixture to reduce until it’s a thick, jammy consistency. Put aside to cool.

Preheat the oven to 175 C/350 F. Line an 8 inch cake tin with parchment paper and grease thoroughly with butter. In a bowl, add the almond flour, sweetener and salt and give it all a goooooood mix. Stir the melted butter into the flour and mix till it comes together like dough. Press the almond flour mix into the cake tin and level it using your fingers, or a spoon, or, anything, really. Bake the base for 10 minutes, then take it out and leave it to cool.

Turn the oven down to 160 C/325 F. In the meantime, make the filling. It’s important to have all the filling ingredients at room temperature to minimise the chance of the cheesecake cracking later. Add the cream cheese and mascarpone to a bowl, along with the sweetener. Whisk it all together until it’s smooth and lump free. Be careful not to whisk it too much, or it will crack later. Add the lemon juice and whisk until just combined. Add the eggs one at a time, and again, whisk until it’s just incorporated. Add the vanilla, whisk, and taste test to make sure the sweetness is fine.

Divide the cheesecake filling into two parts. Stir the berry puree into one part. Then, alternating the two, spoon one ladle of the vanilla mix, then one of the berry. Do this until you’ve used up both batters. Shake very lightly to level, then bake for 35 to 40 minutes, or until the sides are set but the center still has a bit of a jiggle. Leave it to cool to room temperature on a rack, then chill it in the fridge for at least four hours.