Preheat the oven to 325F and line an 8x8 inch baking pan with parchment paper. Mix the almond flour, melted butter, powdered erythritol, and salt together. Press firmly into the bottom of the pan and bake for 10 minutes. Let it cool while you prepare the filling.
Beat the cream cheese and powdered erythritol together until smooth and fluffy, about 2 minutes. Add the eggs one at a time, mixing on low speed after each. Mix in the vanilla and peanut butter until just combined.
Pour the cheesecake filling over the pre-baked crust and smooth the top. Bake at 325F for 28 to 32 minutes until the edges are set but the center still jiggles slightly. Let it cool completely, then refrigerate for at least 2 hours.
Make the caramel by melting the butter in a small saucepan over medium heat. Add the brown erythritol and stir for 2 minutes until dissolved. Pour in the heavy cream and stir constantly for 3 to 4 minutes until the mixture thickens slightly.Remove from heat, stir in the vanilla and salt, then let cool for 10 minutes until it thickens further but is still pourable.
Pour the caramel evenly over the chilled cheesecake. Scatter the chopped peanuts over the top and gently press them in. Refrigerate for 20 minutes.
Melt the dark chocolate and coconut oil together in a small bowl in the microwave in 30-second intervals, stirring between each. Drizzle the chocolate generously over the bars in a criss-cross pattern. Refrigerate for 30 minutes until everything is set before slicing.