Preheat the oven to 325F and line a muffin pan with 6 parchment or silicone liners.
In a medium bowl, whisk together the almond flour and sweetener. Stir in the melted butter until the mixture begins to clump together.
Divide among the prepared muffin cups and press firmly into the bottom. Bake 7 minutes, then remove and let cool while preparing the filling.
Reduce the oven temperature to 300F. In a large bowl, beat the cream cheese until very creamy, about 90 seconds. Beat in the sweetener until well combined and smooth.
Beat in the sour cream and vanilla, then beat in the egg at the very end, until just incorporated. Do not over-beat the mixture.
Divide the filling evenly between the cups and bake 15 to 20 minutes, until the edges are set but the centers still have a little jiggle to them. Remove and let cool completely in the pan, then refrigerate 2 hours to set.
Remove the cupcakes from the muffin lines so you don't burn the liners. In a small bowl, whisk the granular and brown sweeteners together.
Sprinkle about 1 teaspoon of the sweetener mix on top of each cheesecake and press down lightly to adhere. Light a kitchen torch and run the flame over the tops of the cheesecakes until the sweetener caramelizes.
Return to the fridge for another 30 minutes to allow the topping to harden.
