In a large bowl, mash 2 bananas with a fork until smooth and creamy. Measure the banana puree, you should have ¾ cups in total. If you have less you can add a bit more pumpkin puree.
Add pumpkin puree, melted butter, brown sugar, and vanilla extract to the mashed bananas and mix thoroughly.
In a separate bowl whisk dry ingredients: all purpose flour, pumpkin pie spices, baking powder, baking soda and salt.
Add dry ingredients to the pumpkin/banana mixture and stir just until there are no big lumps and the butter looks smooth. Don’t overmix it.
Line your pan with muffin liners, then fill each about ¾ full.
Bake for 25-30 minutes until the tops are golden and an inserted toothpick comes out clean. After taking out of the oven, leave them to cool for 5 minutes, then remove from the pan and place onto a cooling rack to cool completely.
To prepare the glaze, combine all ingredients in a small saucepan and place on medium heat. Stir until the butter melts and the sugar dissolves. Bring to simmer, reduce heat to low and continue to cook, stirring, for 3 minutes. Let cool slightly before glazing the muffins, but not completely because the glaze will harden when cooled.
Notes
To store: Store these muffins in an airtight container at room temperature for up 3 to 4 days. If you’d like to keep them longer, they can be frozen in a zip-top bag or airtight container for up to 3 months.You can let frozen banana pumpkin muffins thaw on the countertop at room temperature, or you can microwave them until they’re warmed through.