In a large mixing bowl, combine the rolled oats and buttermilk. Let that sit for 15 minutes. (I make the berry sauce now and keep it warm over low heat until the pancakes are ready.)
In a medium mixing bowl, combine the all-purpose flour, whole wheat flour, sugar, baking soda, baking powder, salt, and cinnamon. Set aside.
Add the eggs, milk, and mashed banana to the bowl with the buttermilk mixture. Beat until combined. Add the dry ingredients and stir until just combined.
Place a large skillet over medium-high heat (for an electric skillet, heat to 350 degrees F). Grease the pan with non-stick cooking spray.
Pour 1/4 cup of pancake batter onto the hot skillet, leaving space for the pancakes to spread. Cook for 2-3 minutes until bubbles form, then flip and cook for 1-2 minutes until cooked through.
Transfer to a plate and repeat with the rest of the pancake batter. (I like to keep the cooked pancakes warm in the oven set to WARM or 200 degrees F.)
Berry Sauce
Add the blueberries, blackberries, sugar, water, and cinnamon to a medium saucepan. Cook over medium heat until it comes to a boil, about 6-8 minutes. Stir occasionally, breaking up the berries as they cook.
Pour the warm berry sauce over the pancakes and enjoy!
Notes
Nutritional information is for 3 pancakes and 1/4 of the berry sauce.