Preheat oven to 425 degrees.
Spray two or three six-cavity donut pans with cooking spray.
Set aside.
In a large mixing bowl, whisk flour, baking powder, baking soda, salt and sugar.
Set aside.
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 into the flour mixture and 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 and a toothpick inserted in center comes out clean.
Remove from oven and cool approximately 2 minutes on a cooling rack.
Remove donuts from the pan and dip in vanilla glaze.
Place donuts on rack for about 2 minutes before dipping in glaze again.
Finally, dip donuts in glaze a third time.
Immediately sprinkle donuts with colored sprinkles before glazing the next donut.
Set out on wire racks until icing sets, approximately 10 minutes.
Serve.