In a microwave-safe bowl, ramekin or mug that holds at least 12 fluid ounces/1½ cups, whisk together the chocolate hazelnut spread and egg until smooth.
Sprinkle with the baking powder and whisk until combined.
Microwave until the edges are set but the middle is still slightly wet, 40 to 60 seconds.
Top with a spoonful of ice cream or yogurt, if desired, and eat right away.
