Grease and flour a 9x5-inch loaf pan and preheat the oven to 350 F.
Whisk the all-purpose flour, oat flour, baking soda, pumpkin pie spice, and salt in a medium-sized bowl. Set aside.
Mix the mashed bananas, brown sugar, egg, vanilla extract, oil, applesauce, and milk in a large bowl, using a whisk, until well combined.
Fold in the shredded carrots and coconut.
Stir in the dry ingredients using a spatula or wooden spoon until combined. Do not overmix.
Pour the batter into the prepared pan and bake for 40-55 minutes, or until a toothpick inserted in the middle comes out clean.
Let the loaf cool down in the pan for 10 minutes, unmold, and transfer it to a cooling rack to cool down completely.
Make the frosting by mixing the cream cheese, powdered sugar, and cinnamon.
Spread the frosting on top of the cold loaf and sprinkle the chopped pecans over the frosting.