Preheat oven to 350 degrees Fahrenheit
Whisk together all ingredients except flour and blueberries
In a separate bowl, lightly coat the blueberries in some of the flour to prevent them from sinking
Add the flour into the wet ingredient mixture and gently mix
Fold in blueberries. The batter should be thick
Using a spatula, put the batter in a piping bag or a ziploc bag and use a pair of scissors to cut one corner open
Pipe the batter in the donut pan, or gently pipe into a donut shape on a baking tray
Bake at 350 for 8-10 minutes. Let cool completely before adding glaze.
While the donuts bake and cool, whisk together the glaze ingredients and then pour oven donuts. The color will become more transparent as it sits