In a large mixing bowl, whisk together the mashed banana, pumpkin puree, eggs, coconut oil, almond milk, vanilla and brown sugar until smooth.
In another bowl, stir together the flour, baking powder, baking soda, salt and spices. Dump the dry ingredients into the wet and use a rubber spatula to stir until no dry spots remain. Let the batter rest for 10-15 mintues.
Meanwhile, preheat the oven to 350 F and prepare a 9x5 inch loaf pan with non-stick spray and parchment paper for easy removal. Pour the batter into the pan.
In a bowl, stir together the flour, brown sugar, cinnamon and chopped walnuts for the struesel. Add in the room temperature butter and use a fork to combine the ingredients until crumbles form. Sprinkle the topping over the batter and bake for 30-40 minutes. Remove and cover with tin foil and continue baking for additional 15-20 minutes. Let cool before serving. Store the bread in an airtight container for at room temperature for 3 days or in the refrigerator for 5 days.