Preheat oven to 350 degrees F. Spray a loaf pan with cooking spray and set aside.
In a large bowl, combine dry ingredients for the bread: flour, cinnamon, baking powder, baking soda, salt, nutmeg, and sugar. In a separate bowl, combine wet ingredients: egg, applesauce, coconut oil, milk, and vanilla. Whisk to combine.
Add dry to wet ingredients, stirring until combined. Fold in diced apple.
Spread batter into prepared loaf pan.
In a small bowl, combine topping ingredients. Top loaf batter with crumb topping.
Bake for 45-50 minutes until a toothpick comes out clean.
Let cool completely before slicing.