Preheat the oven to 350 degrees and grease a standard muffin pan. Line with cupcake liners if desired.
In a small bowl, mix the flour, baking soda, salt, and cinnamon. Set aside.
In a large bowl, mix together the eggs, mashed banana, pumpkin puree, oat milk, coconut oil, and pure maple syrup. Add the dry ingredients to the wet ingredients and stir to combine well. Stir in the chocolate chips, if using.
Transfer the batter to the prepared muffin pan. Bake the muffins for 20 to 22 minutes, or until the muffins are set and a toothpick inserted in the center comes out clean. Carefully remove the muffins from the pan, and cool completely on a wire rack.