Preheat oven to 425 degrees, and spray donut pans with a light coating of baking spray.
Combine cake flour, granulated sugar, baking powder, cinnamon and salt in a large mixing bowl. Add buttermilk, eggs, and butter, and stir until just combined. Fold in crushed blueberries.
Spoon batter into each donut cup, filling to approximately 2/3 full.
Bake at 425 degrees for approximately 7-9 minutes, and cool in pans for 4-5 minutes before removing.
While the donuts are cooling, mix confectioners' sugar, milk, and vanilla extract together to form the glaze.
Turn the baked donuts out onto a cooling rack and drizzle with glaze.
Serve while still warm.
Have you tried this recipe?
Leave a comment below and share a photo on Instagram. Tag it @unsophisticook and hashtag it #unsophisticook!