Preheat your oven to 350°F (175°C). Line a muffin tin with liners or grease it with cooking spray.
In a large bowl, whisk together the flour, baking soda, baking powder, cinnamon, and brown sugar until well combined.
In another bowl, combine the pumpkin puree, melted butter, eggs, and vanilla extract. Whisk until smooth and homogeneous.
Gradually add the wet ingredients to the dry ingredients, stirring gently until just combined. Avoid overmixing.
Fold in the chocolate chips delicately until evenly distributed throughout the batter.
Fill each muffin cup about two-thirds full with batter. This will allow room for rising.
Place the muffin tin in the preheated oven and bake for 18-20 minutes or until a toothpick inserted in the center comes out clean.
Remove the muffins from the oven and let them cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.