Add brown sugar, cocoa powder, peanut butter, baking powder, and milk to a microwave safe mug. Mix everything until it forms a batter.
Flatten the batter with the back of a spoon for an even top and add some chocolate chunks on top if you like. Microwave on the highest power level for 45 seconds to 60 seconds. Every microwave is different so it may take you more or less time than it took me (took me exactly 55 seconds). Make sure to check after 40 seconds first, then add it back if it's not cooked fully.
Let it sit for 2 minutes after it's cooked and then dig in!
Video
Notes
You can use any other milk if you don't have almond milk but other milks could increase the number of calories in it,
I added chocolate chunks on top just for an aesthetic picture, it will increase the calories a bit so don't add them if you are counting calories.
I used creamy & unsalted natural peanut butter to make the recipe as healthy as possible but if yours is salted that is fine too, just make sure it isn't chunky.
This recipe has 155 calories (excluding the chocolate chunks) and 5g of protein.