Preheat oven to 425 degrees.
Spray 20-cavity donut pan with cooking spray.
Combine 1/3 cup flour and blueberries in a small mixing bowl.
In a large mixing bowl, whisk remaining flour, baking powder, baking soda, salt and granulated sugar.
In a medium sized mixing bowl, whisk the milk, sour cream and eggs until smooth.
Whisk in melted butter, canola oil, and 2 teaspoons vanilla extract.
Pour the butter mixture and blueberries into the flour mixture.
Stir just until combined.
Do not overmix.
Batter will be very thick.
Spoon batter into a large zip-lock bag.
Trim a corner off the bottom of the bag and pipe batter into each donut cavity.
Fill each cup 3∕4 full.
Bake for 10 minutes at 425 degrees or until the edges are lightly browned.
Remove from oven and cool approximately 2 minutes on a cooling rack.
Remove donuts from the pan and dip in vanilla glaze.
Set out on wire racks until icing sets, approximately 10 minutes.