1. Combine Dry Ingredients: In a microwave-safe mug (about 12-14 ounces), add the chocolate protein powder, unsweetened cocoa powder, granulated sugar (or sweetener), baking powder, and a pinch of salt. Use a small whisk or a fork to thoroughly mix these dry ingredients until there are no clumps. This ensures even distribution of the leavening agent and flavor.

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

3. Mix Until Just Combined: Stir everything together with your fork or whisk. Mix until the batter is smooth and no dry pockets of flour or protein powder remain. Be careful not to overmix; a few small lumps are okay. Overmixing can lead to a tough cake.

4. Stir in Chocolate Chips (Optional): If you’re using chocolate chips, gently fold them into the batter now. This will allow them to melt beautifully into the cake as it cooks.

5. Microwave the Mug Cake: Place the mug in the microwave. Cook on high for 60-90 seconds. Cooking times can vary based on your microwave’s wattage. Start with 60 seconds and check for doneness. The cake should look set and slightly springy to the touch. It might still be a little moist in the center, which is perfect for a mug cake.

6. Cool Slightly and Serve: Carefully remove the hot mug from the microwave. Let the mug cake cool for about 1-2 minutes before digging in. This allows it to set a bit more and prevents you from burning your tongue. Enjoy it straight from the mug!