Preheat the oven to 400°F. Grease each soufflé ring or ramekin (3 inches in diameter x 2 inches tall) with butter and then dust with cocoa. You will need 4 to 6 ramekins depending on how big yours are.

To make the soufflé batter, microwave chocolate and butter in the microwave in 30 second intervals stirring in between until melted and smooth. Set aside.

Add the erythritol into the chocolate/butter mixture and mix until combined. In a small bowl, whisk the eggs. Add eggs to chocolate mixture and mix at low speed for 1 minute until mixture is smooth and erythritol is dissolved. Chill in fridge until ready to be used. This can be kept in the fridge for up to 10 days.

Fill each ring mold or ramekin with batter ¾ of the way full. Bake on top oven rack for 15-25 minutes; the time will depend on your oven and size of ramekins. You just want to make sure the tops are set but the middle is still gooey. Since every oven is different, it might be smart to test one. Remove baking sheet from oven. Use a knife to and run it around the edge then carefully invert and place on a serving dish. Sprinkle with powdered erythritol if desired. Serve immediately.