Preheat oven to 375F/190C. Spray two large baking sheets with cooking spray or line with parchment paper and set aside.
Optional (if using extra blueberries): let frozen blueberries thaw completely, then drain any excess water. If using fresh blueberries, wash and dry the berries.
In a large bowl, combine the muffin mix, oats, brown sugar, canola oil, milk, and egg. Mix well.
1 (17.8 ounce box) blueberry muffin mix, ¾ cup quick-cooking oats, ¼ cup brown sugar, 1/3 cup canola oil, 1 tablespoon milk, 2 small eggs or 1 extra large egg
Gently fold in any additional blueberries.
Use a tablespoon to drop dough onto prepared baking sheets. If the dough is very sticky, just keep your hands and your tablespoon wet so that the batter doesn’t stick too much.
Bake for 10-15 minutes, or until just set.