In a medium bow, mash the banana until very smooth with few or no lumps.
Add cinnamon, egg , flour and blueberries to it and mix until everything is combined.
Heat a griddle on medium heat and coat with unsalted butter. Add a heaping tablespoon of the batter to the griddle. Cook for 2-3 minutes or until the sides are starting to become firm golden brown. Flip the pancake and cook the other side to golden brown.
Once cool, serve the pancake to the baby. Let me them pick it up from the tray and enjoy it.