In a large bowl, whisk together flour, sugar, baking powder, soda, and salt. In a small bowl, whisk together buttermilk, eggs, oil, and vanilla. Add wet ingredients to the flour mixture and stir just until combined. Do not over mix. Gently stir in the blueberries and granola. The batter will be slightly lumpy.
Heat a griddle or pan to medium low heat. Coat with cooking spray. Drop about a 1/4 cup of batter onto heated skillet. Cook until surface of pancakes have some bubbles and a few have burst, 1 to 2 minutes. Flip carefully with a spatula, and cook until browned on the underside, 1 to 2 minutes more. Continue making pancakes until the batter is gone. Serve warm with butter and maple syrup, if desired.