The first step is to preheat your oven to 375° F. Grease or line the cups of a muffin tin, set it aside.
In a large bowl, whisk together the pancake mix, brown sugar, baking powder, salt, and pumpkin pie spice until thoroughly combined.
In a small bowl, whisk the avocado oil, egg, and vanilla extract together. Pour into the dry ingredients and mix only until combined. Do NOT over-mix. Add the pumpkin puree, again mixing just until combined. The batter may look slightly lumpy or curdled, but this is okay. Stir in the chocolate chips.
Fill each muffin tin about ¾ the way full. Bake for 20 to 25 minutes, until golden brown or until a toothpick inserted into the center comes out clean. Allow muffins to cool before eating.
Store in an airtight container at room temperature for a few days, or in the refrigerator for up to one week.