In a mug or ramekin, blend together the egg and the cream with a fork.
Add one tablespoon of cocoa powder and whisk until incorporated. Then add the second tablespoon of cocoa powder and blend until smooth.
Now, stir in the powdered sweetener until no lumps remain.
Place the square of dark chocolate on top of the batter. Alternatively, use sugar free chocolate chips.
Microwave for about 1 minute until the mug cake starts to fold away from the edges and the chocolate square has melted. Mine took 70 seconds (900W). Eat while warm.
4.4g net carbs per serving. Makes 1 serving. Microwave timings vary according to power level / wattage. Suggested timings:
800W: 80 seconds
900W: 70 seconds
1000W: 60 seconds
Unlike ovens, microwaves cook from the inside out. That's why I've added the chocolate to create the molten centre. For a larger molten centre, use 2 squares of sugar free chocolate or 2 tbsp sugar free chocolate chips. This increases the net carbs to 5.1g (289 calories).To cook this cake in the oven, I'd go for 180 C / 350F (conventional) and around 9-11 minutes. This way, you'll get a "proper" molten centre.