Combine flour, sugar, oat flour, baking powder, baking soda, salt, cinnamon, cloves, nutmeg, and coconut oil in the bowl of a stand mixer fitted with a paddle attachment. Mix on low until coconut oil disappears into a mealy powder. Add banana mash and continue mixing only until the floury bits disappear. Fold in nuts with a flexible spatula, scrape into prepared pan(s), and spread into an even layer. Bake until well risen and golden brown, or to an internal temperature of around 206°F (about 70 minutes for a large loaf or 45 for small). Wrapped tightly in foil, banana bread will keep up to 3 days at room temperature or 1 week in the fridge.