Prepare wet ingredients: In a large bowl, whisk together milk, mashed banana, egg, vanilla extract, and maple syrup until well combined.
Mix dry ingredients: In a separate bowl, whisk together flour, protein powder (if using), chia seeds, baking powder, cinnamon, and salt.
Combine: Add dry ingredients to wet ingredients and stir until just combined. Don't overmix – a few lumps are okay.
Adjust consistency: If batter is too thick, add milk 1 tablespoon at a time. If too thin, add flour 1 tablespoon at a time.
Add berries: Gently fold in blueberries.
Cook: Heat oil, butter, or ghee in a non-stick pan over medium heat. Pour 1/4 cup of batter per pancake. Cook for 2-3 minutes until bubbles form on surface, then flip and cook 2-3 minutes more until cooked through.
Serve: Transfer to plates and repeat until all batter is used. One serving equals 2-3 pancakes (4-inch size). Enjoy immediately!