Preheat oven to 350° and spray the donut baking pan with oil spray.
Combine all wet ingredients in a mixing bowl and whisk well. Sift in dry ingredients and whisk until incorporated.
Scoop the batter into a large piping bag. Cut the tip off the piping bag, leaving only about 1/2- 3/4 inch opening.
Squeeze batter into the donut cups of the pan in one smooth circular motion, filling each cup almost all the way full. Make sure there is an even amount of batter all around.
Bake for about 15 minutes and let donuts cool on the wire rack. Spread paper a sheet of parchment paper under the cooling rack to catch glaze drippings.
Glaze:
Add powdered sugar into a small mixing bowl.
Heat up heavy whipping cream and whisk in vanilla extract. (You can heat it up in a microwave for just a few seconds.)
Pour the mixture into powdered sugar and whisk until completely incorporated.
Dip each donut into the glaze to coat it on the top and sides. You can dip it on the bottom as well, if you wish.