In a large mixing bowl, whisk together the flour, brown sugar, baking powder and cinnamon. Add the milk, vanilla, melted butter and egg, and whisk until well combined. Stir in the pumpkin and banana.Melt some butter on a skillet or griddle over medium heat. Using a small ladle or ¼-cup measuring cup, scoop batter onto hot griddle. Cook until bubbles begin to appear on top of the pancake, then flip and cook until golden on both sides, about 2-3 minutes per side.To make the syrup, whisk the pumpkin, maple syrup and pumpkin pie spice in a small pan over low heat until warm and smooth. Serve warm syrup over warm pancakes.