Preheat the oven to 350°F and line an 8x8 inch baking pan with parchment paper, leaving an overhang. Stir together the almond flour, brown sugar substitute and salt, then mix in the cooled melted butter, heavy cream and vanilla until a soft dough forms. Fold in the chocolate chips.
Press two thirds of the cookie dough firmly into the pan and bake for 8 minutes. Keep the remaining dough in the fridge and reduce the oven to 325°F.
Beat the cream cheese and powdered sweetener until smooth. Mix in the sour cream and vanilla, then add the eggs one at a time on low speed just until combined.
Pour the cheesecake filling over the cookie crust and smooth the top.
Pinch the chilled cookie dough into small chunks and scatter them all over the filling, then sprinkle with the extra chocolate chips.
Bake for 30 to 35 minutes, until the cookie dough pieces are lightly golden and the center jiggles just slightly.
Cool for 1 hour at room temperature, chill for at least 4 hours, then lift out using the parchment and slice into 16 bars.