Combine all ingredients except blueberries in an oversized microwave-safe mug. Mix with a small whisk until batter is smooth. Stir in blueberries (Make sure you stir these into the batter. If you leave them on top they might burst open onto your microwave).
Cook in microwave for about 1 minute. If cake is not done, heat an additional 15 seconds. Let cake cool a few minutes before eating. Cake is best consumed while still warm or within a few hours of it being cooked.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.