1. Prepare the oat base: In a blender, combine the old-fashioned rolled oats and milk. Blend on high until the oats are mostly broken down and the mixture is smooth, resembling a thin batter. This step is crucial for achieving a uniform pancake texture.

2. Add the wet ingredients: To the oat mixture in the blender, add the mashed ripe bananas, eggs, melted butter or coconut oil, and vanilla extract. Blend again until all the ingredients are well combined and the batter is smooth. Scrape down the sides of the blender if necessary to ensure everything is incorporated.

3. Incorporate the dry leavening agents and spices: Add the brown sugar (if using), baking powder, baking soda, ground cinnamon, and salt to the blender. Pulse a few times until just combined. Be careful not to overmix at this stage; a few pulses are enough to distribute the leavening agents.

4. Heat your griddle or pan: Place a large non-stick griddle or frying pan over medium-low heat. Lightly grease it with a little butter or coconut oil. You’ll know it’s ready when a drop of water sizzles and evaporates quickly. Maintaining a medium-low heat is key to ensuring the pancakes cook through without burning.

5. Cook the pancakes: Pour about 1/4 cup of batter per pancake onto the hot griddle. Cook for 2-3 minutes per side, or until golden brown and bubbles begin to form on the surface of the pancakes. The edges should look set, and the center should appear mostly dry before flipping.

6. Flip and finish: Carefully flip the pancakes with a spatula and cook for another 1-2 minutes on the second side, until golden brown and cooked through. Repeat with the remaining batter, greasing the pan lightly between batches as needed. Serve immediately while warm.