In your mug, add the 2 tablespoons of all-purpose flour, 1/8 teaspoon of baking powder, a small pinch of kosher salt, and 1 1/2 teaspoons of sugar. Use a fork to mix these ingredients together until well combined.
Next, add 1 1/2 teaspoons of coconut oil (melted), 1 1/2 teaspoons of honey, and 2 tablespoons of milk to the dry mixture. Stir until the batter is smooth and everything is evenly incorporated.
Gently fold in 1 tablespoon of fresh blueberries into the batter. This step adds a burst of juicy sweetness that makes your muffin even more delightful.
Place your mug in the microwave and cook on high for about 1 minute. Keep an eye on it as microwave times may vary. You want the muffin to rise and set but not overflow.
Once the muffin is done, carefully remove it from the microwave (it will be hot!). Allow it to cool for a minute or two before digging in. Enjoy your warm, fluffy Muffin In A Mug right from the mug or transfer it to a plate if you prefer.