Preheat the oven to 350F and line a 9 inch springform pan with parchment. Mix the almond flour, cocoa powder, melted butter, sweetener and salt, press into the pan and bake for 10 minutes. Cool and reduce the oven to 325F.
Beat the cream cheese and brown sweetener for 2 minutes until smooth. Add the eggs one at a time on low speed, then mix in the sour cream and vanilla. Fold in the chopped pecans.
Pour the filling over the crust and bake for 50 to 55 minutes until the edges are set and the center jiggles slightly. Turn the oven off, crack the door and cool inside for 1 hour, then chill for at least 6 hours.
Make the caramel. Melt the butter in a saucepan over medium heat, add the allulose and cook, stirring, for 3 to 4 minutes until it turns golden amber.
Slowly whisk in the heavy cream, it will bubble, then simmer for 3 to 4 minutes until thickened. Stir in the vanilla and salt and let cool for 10 minutes until pourable but not hot.
Pour the caramel over the chilled cheesecake and arrange the toasted pecan halves on top, pressing them lightly into the caramel.
Melt the chocolate chips with the coconut oil in 20 second bursts, stirring between each. Drizzle over the pecans and refrigerate for 20 minutes to set before slicing.