Spray a small ramekin bowl or microwave-safe mug with nonstick cooking spray.
Add brown sugar, oil, egg, flour, cocoa powder, baking powder, and salt, and mix well.
Fold in mini chocolate chips.
Microwave the mug or ramein for 45 seconds.
Carefully remove the hot dish from the microwave oven.
Let stand for a few minutes before serving with vanilla ice cream.
Notes
After the fudgy brownie is cooked, stir in peanut butter or Nutella for a more rich dessert. Use a microwave-safe ramekin or mug, and be aware that removing the dish can be very hot. Oven mitts may be needed.