Preheat the oven to 325°F (163°C). Line a 9 × 5-inch loaf pan with parchment paper, or thoroughly coat it with coconut oil or coconut oil cooking spray.
Place the gluten-free rolled oats in a blender or food processor. Process until the oats develop a fine, flour-like consistency. Measure 2 cups of the freshly ground oat flour, reserving any excess for another purpose.
In a large mixing bowl, whisk the honey or maple syrup with the vanilla extract and pumpkin purée until evenly blended.
Add the room-temperature eggs and whisk thoroughly. Incorporate the mashed banana and almond milk, continuing to whisk until the wet mixture appears smooth and uniform.
In a separate smaller bowl, combine the prepared oat flour, baking soda, salt, cinnamon, and pumpkin pie spice. Stir until the leavening and seasonings are evenly distributed.
Add the wet mixture to the dry ingredients. Fold gently until the batter is fully combined and no visible pockets of dry flour remain. Do not overmix.
Fold in the dairy-free chocolate chips, when using, taking care to distribute them evenly without excessively stirring the batter.
Transfer the batter to the prepared loaf pan. Use a spatula to spread it evenly and smooth the surface.
Bake for 35–45 minutes, or until a toothpick inserted into the center of the loaf comes out clean.
Allow the bread to rest in the pan for 10 minutes. Carefully remove it from the pan, place it on a wire cooling rack, and let it cool for an additional 20 minutes before slicing.