Mix Dry Ingredients:
In a microwave-safe mug, combine flour, cocoa powder, sugar, baking powder, and a pinch of salt. Mix well with a fork to avoid lumps.
Add Wet Ingredients:
Stir in the milk, vegetable oil, and vanilla extract until a smooth batter forms.
Optional Chocolate Chips:
Sprinkle chocolate chips on top or mix them into the batter for extra gooeyness.
Cook in Microwave:
Microwave on high for 60-90 seconds. The exact time depends on your microwave's power. Start checking at 60 seconds; the cake should rise and be set but slightly moist on top.
Cool and Enjoy:
Let the mug cake cool for a minute before digging in. Serve as is or top with whipped cream, ice cream, or powdered sugar.