Grease a microwave safe coffee mug with coconut oil or cooking spray.
Place all ingredients in the mug and mix with fork to combine the ingredients.
Microwave on high for 1 minute and 30 seconds to 3 minutes depending on the strength of your microwave. I found that with our microwave, 2 minutes gave a slightly uncooked, soft cake, and 3 minutes for a full baked cake.
Recipe by Healthful Pursuit at https://www.healthfulpursuit.com/2011/11/paleo-chocolate-fudge-vanilla-bean-mug-cakes/