Prepare ingredients: Wash and slice fruit. Slice 3/4 of the bananas for topping and mash the rest for batter.
Make pancake batter: In a bowl, combine mashed banana, ricotta, buttermilk,, and sugar. In a separate bowl, whisk flour, oatmeal, and baking powder. Stir dry ingredients into the wet mixture until just combined.
Cook pancakes: Heat a nonstick skillet over medium heat with a light coating of oil. Pour about ¼ cup batter per pancake. Cook 2–3 minutes, until bubbles form and edges set. Flip and cook for another 2–3 minutes until golden. Repeat with remaining batter.
Assemble: Stack pancakes and top with sliced banana, walnuts, and maple syrup.
Serve the pancakes with mixed fruit and milk.