Set the oven to 350°. Line bread baking dish with parchment paper and spray with cooking spray.
Mash bananas in a mixing bowl, add butter, brown and white sugar, eggs, vanilla, and pumpkin. Whisk until evenly mixed.
In another mixing bowl, mix flour, baking soda, salt, cinnamon, nutmeg, and pumpkin pie spice.
Add flour mixture to wet ingredients mixture (banana + pumpkin batter) and mix. Do not over mix, use a rubber spatula to lightly mix.
Pour mixture into bread baking dish and smooth out the top.
For the streusel topping, mix flour, cinnamon, and brown sugar in a bowl. Add cut cold butter and blend with mixer until it is in crumbles.
Top the banana pumpkin batter with streusel crumbles.
Bake in the center of the rack for 50-65 minutes. To check if done, use a toothpick to poke the center of the loaf. If batter is on the toothpick when you remove it, continue to bake until toothpick comes out clean.
Once baked, let cool and remove this gluten free coffee cake from the baking dish to rest on a baking rack.