• Preheat oven to 350 F. Grease loaf pan, line with parchment paper and set it aside. 
• Add butter and sugar to a large mixing bowl and use hand mixer to combine.
• Add eggs in one at a time, mixing well after each addition and scrape the bowl as needed. Add pumpkin, mashed bananas, vanilla and mix well.
• In a separate bowl, combine dry ingredients. Slowly pour the dry ingredients into the wet ingredients and mix until well combined. 
• In a small bowl, combine brown sugar, flour and cinnamon. Cut softened butter into the mixture until it's all combined and crumbly. 
• Pour batter into prepared loaf pan. Sprinkle streusel topping over the top of the bread batter. In my opinion, the more the merrier. 

Bake at 350 for 70-90 minutes, until a toothpick comes out clean.