Preheat the oven to 350ºF. Line a muffin tin with paper liners (or grease with coconut oil) and set aside.
Beat together wet ingredients in a large mixing bowl. Add dry (minus the blueberries) and stir together until incorporated. Fold in the blueberries.
Divide batter evenly between the muffin cups (this recipe makes about 9 - 10 muffins). Bake on the center rack for 20 - 23 minutes until a cake tester inserted into the center comes out clean.
Allow muffins to cool in the pan for 5 minutes then transfer to a wire rack and cool completely.
Once cooled, make the glaze. Melt the coconut butter over a double boiler until it's smooth and runny. Whisk in blueberry powder and drizzle over muffins. Sprinkle each with a touch more blueberry powder if desired and enjoy!
* if using bagged oat flour, use just 1 cupTo store: Place these healthy blueberry muffins in an airtight container and store them at room temperature for 3 to 4 days, or freeze them for up to 3 months. Frozen muffins can be warmed up in the microwave or left on the countertop at room temperature to thaw.