Grease the donut pan (I used a silicon pan) with cooking spray and set aside.
In the bowl, mix the dry ingredients (flour, baking powder, and salt) and set aside.
In the bowl of a stand mixer, add eggs and granulated sugar. Whisk for 2-3 minutes.
Add melted butter and warm milk. Whisk again until combined.
Add dry ingredients to wet ingredients and mix again. Fold blueberries into the batter gently.
Place batter into a plastic piping bag with the end cut off about ½”. Fill donut cavities about ¾ full.
Bake at 420oF (215oC) for 12-15 minutes or until tops are lightly browned. Let the donuts cool in the pan for 10 -15 minutes before gently inverting the pan and taking the donuts out.
Dip each donut into the lemon glaze. Place onto a wire rack to allow excess glaze to drip down. You can also use a spoon to cover donuts with the glaze.
How to Make Lemon Glaze
Whisk together the powdered sugar and lemon juice. If the glaze is too thick for your liking, add more lemon juice. The glaze works better when the donuts are still a bit warm.
Notes
Prepare all ingredients and tools before baking.Use a kitchen scale to measure all ingredients.