Preheat oven to 375° F. Grease or line a 12-cup muffin pan, set aside.
In a large bowl, whisk together the pancake mix, oats, brown sugar, baking powder, salt, and cinnamon. Remove one tsp of dry ingredients and sprinkle over blueberries. Toss to coat.
In a small bowl, whisk together the avocado oil, egg, and vanilla extract. Pour into the dry ingredients and mix only until combined.
Add the Greek yogurt and milk to the batter, mixing only until just combined. Do not over-mix. Fold in the blueberries.
Scoop the batter into the prepared muffin tins, filling each ¾ of the way full. Sprinkle each cup of batter with the granulated sugar.
Bake for 20-25 minutes, until golden or until a toothpick inserted into the center comes out clean. Allow to cool before eating.
Store in an airtight container at room temperature for up to 4 days, or in the refrigerator for up to a week.