Instructions

In a bowl, whisk together butter, sugar, milk and vanilla extract.
Add baking powder and flour and whisk till combined. Mix in blueberries and pour into two microwave proof tea cups or one mug. Only fill the cups or mugs halfway because the cake rises up quite a bit. To clarify, this recipe is enough for one mug but I was able to divide it into two when I used two tea cups.
Microwave for 1 minute on high. I have a small microwave and I’m not sure about the wattage. Cooking time would vary slightly depending on the size of your microwave, so I recommend starting with 45 seconds and increasing by 30 seconds.
Serve the blueberry mug cake dusted with sugar and topped with more blueberries.