Heat the oven to 325°F. Combine the almond flour, cocoa powder, sweetener and melted butter. Press into a 9-inch springform pan and bake for 9 minutes.
Beat the cream cheese and sweetener until creamy. Mix in the cocoa powder, sour cream, vanilla extract and sea salt until completely smooth.
Add the eggs one at a time on low speed. Pour the batter over the crust and bake for 50 to 57 minutes, until the edges are set and the center still jiggles slightly.
Cool the cheesecake completely and refrigerate for at least 5 hours before adding the topping.
Whisk the egg yolks, heavy cream and allulose in a saucepan. Cook over medium-low heat while stirring constantly until the mixture thickens, then stir in the butter and vanilla extract.
Fold the shredded coconut and pecans into the warm custard. Cool until the topping is thick but still easily spreadable.
Spoon the coconut pecan topping generously over the cold chocolate cheesecake and refrigerate for 30 minutes before serving.