Preheat oven to 400 degrees and line a 12-cup muffin pan with paper liners (or spray with non-stick spray).
In a large bowl, whisk together the flour, xanthan gum, baking soda, allspice, cinnamon, and salt. Stir in the chocolate chips.
In a separate bowl, whisk together the brown sugar, eggs, oil, milk, pumpkin puree, and vanilla. Pour the wet ingredients into the dry ingredients and stir until combined.
Divide the batter equally between the 12 muffin cups and sprinkle with additional chocolate chips if desired.
Bake at 400 degrees for 16-18 minutes or until cooked through. Cool in the pan for 5 minutes before cooling on a wire rack.
Notes
Omit the xanthan gum if your flour blend contains it.
For dairy free, use unsweetened coconut milk beverage and dairy free chocolate chips.