Combine the almond flour, cocoa powder, sweetener, and melted butter in a bowl and mix until the color is evenly dark with no dry pockets. The crumbs should clump when pinched and look like moist chocolate sand.

Transfer the mixture to a 9-inch pie plate and press it down hard across the bottom and up the sides, using the flat base of a measuring cup for even pressure. The surface should feel compact and solid under your fingertips, not loose or powdery.

Slide the crust into the freezer and leave it there while you build the filling. The butter firms up quickly in the cold, locking the base into a sliceable layer.

Beat the room-temperature cream cheese with the peanut butter and sweetener until the mixture turns completely smooth. Expect a very thick, dense paste with a uniform tan color and no white streaks of cream cheese.

Using a separate bowl, whip the heavy cream with the vanilla until stiff peaks form. The cream should hold a sharp point when you lift the beaters, with visible ridges that do not slump back down.

Fold the whipped cream into the peanut butter base, stopping the moment the streaks disappear. The filling will lighten in color and feel billowy rather than stiff, so stop folding as soon as it looks uniform.

Pull the chilled crust from the freezer and spread the filling over it with a spatula, working gently toward the edges. Smooth the top into an even layer with a soft matte finish.

Refrigerate for at least 1 hour before serving. The surface turns from glossy to matte and the filling feels set when touched lightly at the center.