In a mixing bowl combine flour, sugar, baking powder, salt, and cinnamon. In another mixing bowl combine eggs, milk, bananas, and melted margarine or butter or oil. Add to the flour mixture. Stir just until combined but still slightly lumpy. Stir in walnuts or pecans.
Heat a lightly greased griddle or heavy skillet over medium heat until a few drops of water dance across the surface. For each pancake, pour about 1/4 cup batter onto the hot griddle.
Cook over medium heat until pancakes are golden brown, turning to cook second sides when pancake surfaces are bubbly and edges are slightly dry (about 1 to 2 minutes per side). Serve immediately or keep warm in a loosely covered ovenproof dish in a 300 degree F oven. Makes 16 pancakes.