Whisk together the ricotta cheese, butter, honey/syrup, vanilla and egg in a small microwave safe glass bowl or a large microwave safe mug.
Whisk in the flour, baking powder, and salt until combined.
Top with the blueberries.
Microwave on high for 3 minutes.
Remove from microwave and dust with powdered sugar. (Be careful as the bowl/mug will be very hot after cooking in the microwave.)