1. 1. Combine Dry Ingredients: In your microwave-safe mug, add the chocolate protein powder, unsweetened cocoa powder, all-purpose flour, baking powder, salt, and granulated sugar. Use a small fork or spoon to thoroughly whisk these dry ingredients together until there are no lumps and they are well combined. This ensures an even distribution of leavening and flavor.

2. 2. Add Wet Ingredients: Pour in the milk, unsweetened applesauce (or oil), and vanilla extract into the mug with the dry mixture.

3. 3. Mix Until Just Combined: Stir the wet and dry ingredients together using your fork or spoon. Mix until just combined and smooth. Be careful not to overmix; a few small lumps are fine. Overmixing can lead to a tough mug cake.

4. 4. Stir in Chocolate Chips (Optional): If you’re adding chocolate chips, gently fold them into the batter now. They will melt into gooey pockets of chocolate during cooking.

5. 5. Microwave the Cake: Place the mug in the microwave. Cook on high power for 60-90 seconds. The exact cooking time will vary depending on your microwave’s wattage. Start with 60 seconds and then add 10-15 second increments until the cake is set but still slightly moist in the center. The top should look firm and spring back slightly when touched.

6. 6. Check for Doneness: The cake is done when it looks puffed up and the edges are set. If it looks very wet in the center, microwave for a few more seconds. Be careful not to overcook, as this can make the cake dry and rubbery.

7. 7. Cool Slightly and Serve: Carefully remove the hot mug from the microwave. Allow the mug cake to cool for about 1-2 minutes before digging in. This brief cooling period helps the cake set and prevents you from burning your tongue.

8. 8. Add Toppings (Optional): Serve warm, perhaps with a dollop of whipped cream, a sprinkle of extra chocolate chips, or a drizzle of sugar-free syrup.