In a large bowl, whisk together the applesauce, oil, and eggs. Stir in the oat flour, sugar, baking powder, baking soda, cinnamon, nutmeg, and salt.
Pour the batter into the prepared pan. Preheat oven to 350° F. Let batter rest while the oven heats, or up to 20 minutes.
Place in oven and bake for 55-60 minutes, checking after 55 minutes, until a tester comes out clean, the top is slightly firm to the touch, and edges are starting to pull away from the pan. Remove the pan from the oven and place it on a wire rack to cool. Let cook in the pan for 15 minutes, then turn out on the rack to cool completely.
Notes
Rest the batter - Let the batter rest for 20 minutes, or at least as long as the oven preheats. This allows the gluten free flour to hydrate, which will create a fluffier crumb after the bread has baked.
Oat flour substitute - Nice choices for an oat flour substitute include sorghum flour or brown rice flour.
Or just use gluten free four - Swap in 2 ½ cups of gluten free all-purpose flour of your choice (or make my homemade gluten free flour blend) and use it in place of the oat flour.
Use unrefined sugar - Substitute the sugar for coconut sugar or maple syrup if you wish to use a natural sweetener.
Make mini loaves - If you want to enjoy a loaf now and save one for later, bake this recipe into mini loaves. You'll get about 2 smaller loaves from the batter.