To a large bowl, add oat flour, gluten-free flour, almond flour, baking powder, salt, cinnamon, ginger (optional), and nutmeg (optional). Whisk to combine and set aside.
To a separate mixing bowl, add bananas and mash. Then add melted coconut oil, vanilla extract, maple syrup, and non-dairy milk and whisk to combine. If the coconut oil hardens or clumps, it's not a big deal. You can microwave (for 45 seconds - 1 minute) to remelt - otherwise proceed.
Add the wet ingredients to the dry ingredients and gently fold everything together. Then add the chopped walnuts and oats and gently fold/mix until the batter is well combined. It should be thick but pourable/scoopable.
Heat a large nonstick skillet, griddle, or cast-iron skillet over medium heat. Carefully rub skillet with coconut oil or vegan butter.
Once hot, spoon 1/4 - 1/3 cup of the batter onto skillet. Cook until surface of pancakes have some bubbles and the edges appear dry (~2 minutes). Carefully flip pancakes and cook until browned on the underside (~2 minutes more).
Transfer cooked pancakes to a baking sheet or plate and keep warm in a 200-degree F (94 C) oven. Continue cooking until all batter is used up - about 14-16 pancakes (as original recipe is written).
These pancakes are delicious on their own, but they're amplified with vegan butter or peanut butter, sliced bananas, granola, flaked coconut, and maple syrup. Store cooled leftover pancakes (without toppings) in a container separated with wax or parchment paper to prevent sticking. Will keep in the refrigerator up to 4 days or in the freezer up to 1 month. Reheat in the toaster oven or oven until hot.
*If you can't tolerate oats, you can try subbing a blend of gluten-free flour and almond flour, but I haven't tested it that way and can't guarantee the results. *If nut-free, sub the almond milk for rice or light coconut milk. And sub the almond flour for additional gluten-free flour blend. *If oil-free, try subbing with applesauce or 1 Tbsp nut butter. *Nutrition information is a rough estimate calculated without toppings. *These pancakes are adapted from the Banana Walnut Flapjacks at one of my favorite Portland cafes - Harlow. The recipe was generously shared with me here.