Preheat the oven to 350 degrees and spray a 6-count donut pan with non-stick spray. Set aside.
Blueberry Donuts
In a large bowl whisk together the flour, baking powder, and salt. Set aside.
In a medium-sized bowl, whisk together the melted butter, egg, sugar, milk, yogurt, and vanilla extract until combined. Add the wet ingredients into the dry and gently fold your ingredients together using a silicone spatula or wooden spoon until combined (be careful not to over mix). Then gently fold in the blueberries.
Scoop the batter into a piping bag or a zipped-up sandwich bag. Simply cut a corner off of the bottom of the bag and pipe the donut batter into each donut cup, filling it up just barely to the top.
Bake the donuts for 9-11 minutes (10 minutes is perfect for me). To check if the donuts are done, touch the top of one carefully with your finger. If it bounces back, they're done. You could also take a toothpick to check the center. If it comes out clean, then they're done. Allow the donuts to cool in the pan for 5 minutes before carefully removing them and setting them on a wire rack to finish cooling.
Blueberry Glaze
Add the blueberries and water to a small saucepan and cook over medium heat until the berries are soft and start to break down a little (about 5 minutes).
Strain the berries over a small bowl so the juice is separated from the skins, using a spoon or silicone spatula to press the juices out. Whisk in the powdered sugar and vanilla extract until no more lumps remain. If the glaze is too thin, add an extra 1-2 teaspoon of powdered sugar.
Once the donuts have cooled, dip them into the glaze and place them back onto the wire rack (feel free to dip the donuts twice for extra glaze!). Once set, serve immediately and enjoy!
Keep leftover donuts in an airtight container in the refrigerator for up to 2 days.
Notes:
Donut Pan: You'll need a 6-count donut pan like this one or this wilton donut pan. I have both of these and use them interchangeably. Be sure to spray it with nonstick cooking spray.
Measuring Flour: To help ensure you don’t add extra flour, follow these three simple steps: 1) Fluff up the flour using a fork. 2) Spoon the flour into your measuring cup. 3) Scrape a knife across the top of the measuring cup to level out the flour.
Donut Batter: I find it so much easier to scrape the donut batter into a piping bag or ziplock bag and pipe the batter into the donut mold. This method makes it less messy too.
Glaze: If the glaze is a bit too thin, just add 1-2 teaspoons more of powdered sugar.