Prep the pan and oven: Preheat the oven to 350°F (175°C).
Grease an 8x8-inch baking dish or line it with parchment for easy removal.
Mash bananas: In a large bowl, mash the ripe bananas until mostly smooth. A few small lumps are fine.
Whisk in wet ingredients: Add eggs, milk, melted coconut oil or butter, vanilla, and maple syrup (if using). Whisk until well combined.
Stir in dry ingredients: Add rolled oats, cinnamon, baking powder, and a pinch of salt.
Stir until everything is evenly moistened. Fold in any add-ins.
Rest the batter: Let the mixture sit for 5 minutes so the oats start to absorb the liquid. This helps the bake hold together.
Fill the pan: Pour the mixture into the prepared baking dish and spread it into an even layer.
Bake: Bake for 28–35 minutes, until the top is set and lightly golden and the center no longer jiggles.
Cool and slice: Cool in the pan for at least 15 minutes.
Slice into 9–12 squares for toddler portions.
Serve: Enjoy warm or at room temperature. For younger toddlers, serve with a splash of warm milk or yogurt to soften.