3 Ingredient Chocolate Protein Mug Cake

0 Build the mug cake. Add the chocolate protein powder to a lightly greased mug or ramekin, then add the egg & milk. If you're using it, you may also add the maple syrup and cocoa powder here.
1 Mix. Using a fork or a small whisk, mix the cake batter until smooth & there are no clumps of protein powder remaining. The texture should resemble a thick chocolate mousse. If you're adding chocolate chips, fold them in now.
2 Microwave. Place the mug in the microwave and microwave for 30 seconds. If the mug cake is not fully set, microwave for another 10 seconds. Do not exceed 50 seconds as most protein powders will get a rubbery texture after that point.