Preheat the waffle iron. Set it to medium or the “regular” setting. Lightly grease the plates with oil or butter to prevent sticking.
Mash the bananas. In a large bowl, mash bananas until mostly smooth with a few small lumps.
Toddlers usually prefer smoother waffles, so mash well.
Whisk in wet ingredients. Add eggs, milk, vanilla, and melted butter. Whisk until fully combined.
Mix dry ingredients. In a separate bowl, stir together the flour, quick oats, baking powder, cinnamon, and salt. If using flaxseed or chia, add them here.
Combine gently. Add dry ingredients to the banana mixture and stir until just combined.
The batter should be pourable but thick. If it seems too thick, add 1–2 tablespoons more milk.
Cook the waffles. Pour batter onto the preheated iron, spreading slightly to the edges. Close and cook until lightly golden and set, usually 3–4 minutes depending on your machine.
Avoid over-browning for toddler-friendly softness.
Cool briefly. Transfer waffles to a cooling rack for a couple of minutes. This prevents sogginess while keeping them soft.
Serve. Cut into strips or bite-size squares. Add a smear of yogurt, nut or seed butter, or fresh fruit on top.
For very young toddlers, skip sticky toppings and serve with a little plain yogurt for dipping.