Preheat the oven to 375 degrees F. Spray a doughnut pan with nonstick cooking spray. (NOTE: If using an electric donut maker, read the manufacturer''s directions.)
Combine all dry ingredients in a mixing bowl. Combine all wet ingredients except for blueberries into a separate mixing bowl. Stir the wet ingredients into the dry just until combined, then gently fold in the blueberries.
For mini donuts, drop one tablespoon of batter into each donut form. Use two tablespoons for traditional-size donuts.
Bake for 10 minutes, until golden brown.
Pulse the sugar and lemon zest in a mini food processor until combined.
Place the lemon sugar into a resealable bag. Working with two at a time, place the donuts in the bag and shake well to coat. Transfer the donuts to a wire rack to cool, if they make it that far!
Makes 10 regular-size doughnuts or 20 mini doughnuts
