In a bowl, whisk together the flour, sugar, baking powder, cinnamon, baking soda, and salt. Make a well in the center.

In another bowl, whisk the milk, bananas, melted butter, and vanilla extract together. Add in the egg and whisk together. Pour mixture into the well in the flour mixture; stir until just combined. Fold in the walnuts.

Heat a lightly oiled skillet or griddle over medium heat. Drop 1/4 cup batter onto the skillet or griddle and gently spread batter evenly with the back of a spoon. Cook until bubbles form and the edges are firm, 3 to 4 minutes. Flip and cook until browned on the other side, 1 to 2 minutes more. Repeat with remaining batter. Makes 6-8 pancakes. Serves 3-4.