Step 1

In a microwave-safe mug that can hold at least 8 oz of liquid, add all mug cake ingredients except lemon zest. Mix with a small whisk until batter is smooth.

Step 2

Stir in 1/4 tsp lemon zest. Add a little more zest over surface of the cake. This should only be about a pinch worth spread out across the surface.

Step 3

Cook the cake in the microwave for about 1 minute and 40 seconds. Let cake cool slightly before dusting with powdered sugar substitute (like Swerve) or other topping of your choice. Cake is best consumed shortly after it is cooked.