Preheat oven to 350 degrees.
In a large mixing bowl, whisk together milk and maple syrup. Whisk in egg.
Add the canned pumpkin to the mixing bowl and whisk as thoroughly as you can. Try to get most of the large clumps of pumpkin broken apart.
Add dry ingredients (oats, pumpkin spice, baking powder, and salt) to the wet ingredients and stir to combine.
Add in option pecans and/or chocolate and stir.
Using a spoon or 1/4 cup measuring cup, spoon the mixture into lightly greased muffin tins or silicone muffin cups.
Bake in preheated oven for 30 minutes. Allow to cool before removing from muffin molds.