In a large bowl, mix the flour, baking powder, baking soda, salt, cinnamon, and pumpkin pie spice. Let aside.
2 cups All-purpose flour, 1 teaspoon Baking soda, 2 teaspoon Baking powder, ½ teaspoon Salt, 2 teaspoon Ground cinnamon, 1 teaspoon Pumpkin pie spice
In a bowl, line it with 2 paper towels and add the pumpkin puree. Cover it with the paper towels and let the towels soak in the moisture. Let sit for 1-2 minutes. Do this twice to get rid of the moisture. Mash a ripe banana on a plate using a fork or a potato masher.
¾ cup Pumpkin puree, ¼ cup Banana
In a medium bowl, mix the melted butter (make sure it is cooled to room temperature before using), sour cream, pumpkin puree, mashed banana, brown sugar, sugar, vanilla, and eggs. Use a whisk to mix it together.
½ cup Unsalted butter, ¼ cup Sour cream, ½ cup Brown sugar, ¼ cup White granulated sugar, 1 teaspoon Pure vanilla extract, 2 Large eggs
Pour the wet ingredients into the dry ingredients. Mix until just combined. Make sure to not over mix!
Preheat the oven to 425°F. Line a 12 cup muffin pan with 6 muffin liners. Separate them through out the pan. This helps to get them a taller rise.
Scoop the muffin batter using a cookie scoop. The muffin liner should be completely full.
Take the streusel out of the fridge. Use your hands to break up the clumps. Sprinkle a good heaping on top of muffins.
Bake for 5 minutes at 425°F. Reduce the heat to 375°F and bake for 11-13 minutes. Bake until a toothpick inserted comes out clean.
Let the muffins sit in the hot pan for 10 minutes before transferring to a cooling rack.