In a microwave-safe bowl or mug, combine melted cocoa butter, cream and peppermint extract. Whisk until combined.
Add all remaining ingredients, in the order listed, then whisk until incorporated and creamy. Microwave on ‘high’ for 75 seconds, until just firm to touch on top.
Serve immediately with toppings of choice!
If you want to make a few mug cakes at once, microwave separately for only 60 seconds, then once cool, keep tightly sealed in the refrigerator up to 4 days. Microwave for 20 seconds to reheat.