Place 1 cup old-fashioned rolled oats in a blender or food processor. Pulse until oats reach a coarse flour-like texture (about 20–30 seconds). This gives a smoother pancake without needing all-purpose flour.

Mash bananas

In a medium bowl, mash 1.5 cups ripe bananas (about 2–3 medium bananas) with a fork until mostly smooth with a few small lumps remaining for texture.

Combine wet ingredients

To the mashed bananas add 2 large eggs, 3 tablespoons milk, 1 teaspoon vanilla extract and (optional) 1 tablespoon maple syrup or honey. Whisk until combined and slightly frothy.

Combine dry ingredients

In the blender with the ground oats, add 1 teaspoon baking powder, 1/2 teaspoon ground cinnamon and 1/4 teaspoon salt. Pulse briefly to distribute the leavening and spices evenly (5–10 seconds).

Make batter

Pour the banana-egg mixture into the blender with the oat mixture (or transfer blended oat flour into the bowl with the wet ingredients). Blend 5–10 seconds until just combined into a pourable batter. If batter is too thick, add an extra tablespoon of milk at a time until it reaches a thick but pourable consistency (should fall from a spoon in a ribbon). Let batter rest 3–5 minutes to allow oats to hydrate and thicken slightly.

Cooking & finishing

Preheat pan

Heat a nonstick skillet or griddle over medium heat for 3–4 minutes. Add 1 tablespoon butter or oil and swirl to coat the surface. Reduce heat to medium-low if your pan runs hot; you want a steady gentle sizzle when batter hits the pan.

Cook pancakes

For each pancake, pour about 1/4 cup batter onto the hot skillet. If desired, place a few fresh banana slices on top of each pancake immediately. Cook until small bubbles form on the surface and edges look set, about 2–3 minutes. Flip and cook the second side until golden-brown and cooked through, about 1–2 minutes longer. Adjust heat as necessary to prevent burning.

Keep warm

Transfer cooked pancakes to a plate and keep warm in a single layer on a baking sheet in a 200°F (95°C) oven while you finish the rest. Wipe the pan with a paper towel and add more butter or oil as needed between batches.

Serve

Stack pancakes and serve topped with maple syrup, extra banana slices and toasted nuts or seeds if using. Adjust syrup to taste.

Storage

Store cooled leftovers in an airtight container in the refrigerator for up to 3 days or freeze separated by parchment paper for up to 1 month. Reheat in a toaster oven or skillet until warmed through.