Pre-heat oven to 350F and cover donut pan with baking spray.
In large mixing bowl, combine flour, baking powder, salt, and sugar. Gradually stir in whisked egg, milk, almond extract, and melted butter just until combined (be careful not to overmix!)
Carefully fold in blueberries.
Place batter into Ziploc bag with a corner cut out using scissors (or use a pastry bag). Pipe batter into prepared donut pan. Note, you may have a small amount of leftover batter, which if you put in a mug you can microwave for 20-30 seconds for a treat while you wait for the donuts to bake ;).
Bake for 9-10 minutes. Allow to cool while you make the frosting.
To make blueberry glaze, place blueberries, lemon juice, and water in small saucepan over medium heat.
Once the blueberries begin to break down and burst, transfer mixture to a blender. Blend to combine then pour into a small mixing bowl.
Stir in powdered sugar in 1/4 cup increments until smooth (you may not end up using all the sugar).
Dip donuts in the glaze and serve immediately! Once glaze has hardened you can store them using wax paper between layers, but the glaze will start to seep into the donuts after a day or two.