Preheat the oven to 350°F (175°C). Lightly coat a standard 12-cup muffin tin or a 24-cup mini muffin pan with a portion of the melted coconut oil to help prevent sticking.
Place the oat flour and baking soda in a large mixing bowl. Whisk or stir thoroughly so the baking soda is distributed evenly throughout the flour.
Add the eggs, unsweetened applesauce, pure pumpkin puree, and remaining melted coconut oil to the dry mixture. Stir only until the ingredients are incorporated. A few small lumps or faint streaks of flour may remain; avoid excessive mixing so the muffins retain a light, tender texture.
Divide the batter among the prepared muffin cups, filling each cavity approximately two-thirds full.
For standard-size muffins, bake for 15–20 minutes. For mini muffins, bake for 10–15 minutes. Test for doneness by inserting a toothpick into the center of a muffin; it should come out clean.
Remove the baked muffins from the pan and place them on a wire cooling rack. Allow them to cool completely before serving so they can finish setting and develop their intended texture.