Preheat the oven to 350 degrees F. Line a 12-cup muffin tin with baking cups and set aside.
In a large mixing bowl, whisk together the flour, pumpkin pie spice, baking soda and baking powder. Set aside.
In another large bowl, mix pumpkin puree, brown sugar, milk, maple syrup, coconut oil, apple cider vinegar and vanilla extract until well combined.
Stir the dry ingredients into the wet ingredients until just combined.
Divide the batter into the prepared baking cups using a spoon or cookie scoop, filling each cup about 3/4 of the way full. Sprinkle with pepitas, if desired.
Bake for 20 to 23 minutes or until golden brown and cooked through. Enjoy warm or cool!