For the crust: in a medium saucepan over low heat melt butter. Stir in cocoa and erythritol and then slowly whisk in beaten egg. Cook, stirring constantly, until mixture thickens. Remove from heat and stir in almond meal, coconut, nuts and vanilla. Press evenly into bottom and sides of a 9 inch tart pan with removable bottom and refrigerate until firm (30-45 minutes).
In the bowl of a stand mixer fitted with the paddle attachment, beat cream cheese until smooth, about two minutes. Add cream, pudding, almond milk and vanilla and beat until combined. Spread over crust and refrigerate for at least 30 minutes.
In a small saucepan over low, melt butter, unsweetened chocolate and powdered erythritol together. Add cocoa powder and stir until smooth. Remove from heat and stir in stevia extract. Spread over filling and refrigerate until set, about 1 hour.