Pumpkin Banana Muffins

0 Preheat your oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or grease the muffin cups with non-stick spray.
1 In a small bowl, combine the flour, brown sugar, and pumpkin pie spice for the streusel. Add the cold, cubed butter and use a pastry cutter or your fingers to work the butter into the dry ingredients until the mixture resembles coarse crumbs. Set aside.
2 In a large mixing bowl, whisk together the mashed bananas, pumpkin puree (squeeze the excess moisture out of it) , granulated sugar, brown sugar, oil, eggs, and vanilla extract until smooth and well combined.
3 Gradually add the dry ingredients to the wet ingredients, mixing just until combined. Be careful not to overmix; the batter should be slightly lumpy.
4 Divide the batter evenly among the prepared muffin cups, filling each about 3/4 full.
5 Generously sprinkle the streusel topping over each muffin, pressing it down lightly so it sticks to the batter.
6 Bake in the preheated oven for 18-22 minutes, or until a toothpick inserted into the center of a muffin comes out clean or with a few moist crumbs.
7 Allow the muffins to cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.