Preheat the oven to 350°F and spray an 8 x 5-inch loaf pan with cooking spray.
In a medium bowl, sift together the flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
In a large bowl, mash the overripe bananas until smooth.
Add the granulated sugar to the mashed bananas and beat until smooth.
Add the eggs, vegetable oil, and apple butter. Blend until well combined.
Add the dry ingredient mixture to the banana mixture and blend until combined.
Pour the batter into the prepared loaf pan.
To make the pecan streusel, combine the brown sugar, diced pecans, flour, cinnamon, and cold diced butter in a small bowl.
Work the butter into the other ingredients until the mixture becomes crumbly.
Sprinkle the streusel evenly over the bread batter.
Bake for 45–50 minutes. Begin checking after 45 minutes by inserting a toothpick into the center. The bread is ready when the tester comes out clean.
Allow the bread to cool before slicing and serving.