Preheat oven to 400F and move the rack to the middle position and grease a 12-cup muffin tin (I use Pam cooking spray).
In a large bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and pumpkin spice.
In a smaller bowl, whisk together the milk, canola oil, egg, pumpkin purée, and vanilla.
Pour the wet ingredients into the bowl with the dry ingredients. Gently mix it together (I just use a wooden spoon), taking care not to overwork it. Fold in the chocolate chips.
Fill each cavity in the muffin tin about 3/4 full.
Bake for 18-20 minutes or until they're lightly browned on top. I bake mine for 20 minutes.
Let cool in muffin tin for a few minutes then transfer to a wire rack to finish cooling.