Begin by selecting a microwave-safe mug that has a capacity of at least 12 ounces to prevent overflow. In the mug, combine the all-purpose flour, granulated sugar, unsweetened cocoa powder, baking powder, and salt. Use a fork or small whisk to stir the mixture thoroughly, ensuring there are no lumps.
Next, pour in the milk, followed by the peanut butter, vegetable oil, and pure vanilla extract. Mix these wet ingredients into the dry ingredients carefully until you achieve a uniform, smooth batter. Ensure that there are no streaks of dry flour remaining in the mug.
For an indulgent chocolate boost, gently fold in a handful of chocolate chips into the batter, distributing them evenly.
Place the mug in the microwave and cook on high for approximately 40 to 60 seconds. Keep a careful watch; microwave wattages vary, and you want the cake to rise and be set but still slightly moist in the center for the best texture. If the cake isn’t fully cooked, you can microwave it in additional 10-second increments.
Once ready, let the mug cake cool for about a minute, as it will be hot. For enhanced flavor and presentation, consider topping your mug cake with a dollop of whipped cream or a drizzle of melted chocolate, if desired.
Notes
For enhanced flavor, top with whipped cream or melted chocolate.