Preheat the oven to 425°F (220°C). Line a muffin tin with paper liners or spray with cooking spray.
In a large bowl, whisk together the flour, sugar, pumpkin pie spice, baking powder, baking soda, and salt.
1 ¾ cups all-purpose flour, 2 teaspoons pumpkin pie spice, 1 teaspoon baking soda, 1 teaspoon baking powder, ¼ teaspoon salt, 1 cup granulated sugar
In a separate bowl, combine the pumpkin purée, oil, eggs, and vanilla extract. Whisk until smooth.
1 cup canned pumpkin purée, ½ cup vegetable oil, 2 large eggs, 1 teaspoon vanilla extract
Gradually fold the dry ingredients into the wet mixture until just combined. Avoid overmixing.
Gently fold 1 cup of chocolate chips into the batter.
Scoop the batter into the prepared muffin tin, filling each cup about ⅔ full. Use the remaining ½ cup of chocolate chips to dot over unbaked batter.
Bake at 425°F for 5 minutes, then reduce the oven temperature to 350°F (175°C). Continue baking for an additional 13-17 minutes, or until a toothpick inserted in the center comes out clean.
Let the muffins cool in the tin for a few minutes, then transfer them to a wire rack to cool completely before serving or storing.