Preheat oven to 160°C (320°F) and grease a springform pan.
Mix almond flour, melted butter, and sweetener, then press into the pan for the crust.
Bake crust for 10 minutes and let it cool.
Beat cream cheese and sweetener until smooth.
Add eggs one at a time, mixing gently.
Stir in vanilla extract and heavy cream.
Pour most of the batter over the crust.
Mix remaining batter with cocoa powder and melted chocolate.
Drop chocolate mixture on top and swirl with a knife.
Bake for 40 minutes, then cool and refrigerate for at least 4 hours.