Place medium sized non-stick skillet over medium heat.
Place flour, oats, baking soda, salt and walnuts into a large mixing bowl. Stir to combine then pour in buttermilk, egg and vanilla, mixing to combine.
Spoon about 1/4 cup batter into hot skillet, swirling to make round. Cook until browned then flip to brown other side. Remove and stack onto plate. Continue finishing pancakes until batter is gone. To serve, layer sliced bananas around edges of each pancake and drizzle with warm caramel sauce.