Whisk together the flour, salt, baking powder, baking soda, cinnamon, and pumpkin pie spice.
In a separate bowl, whisk together the mashed banana, pumpkin, melted butter, eggs, vanilla extract, brown sugar and sugar.
Add the dry ingredients to the wet and mix until just combined using a rubber spatula. Do not over mix the batter.
Line a muffin tin with parchment paper muffin liners (nothing will stick to these). Or spray your muffin tin with cooking spray.
Fill the muffin tins ¾ of the way full. The recipe will make 14 muffins.
Bake the muffins at 350 degrees for 23-25 minutes, or until a toothpick inserted comes out clean