Heat oven to 350°F. Grease a 9x13-inch pan and line the bottom with parchment.
Whisk flour, baking powder, baking soda, salt, cinnamon, and pumpkin pie spice in a medium bowl.
Whisk pumpkin, oil, granulated sugar, brown sugar, eggs, and vanilla in a large bowl until smooth.
Add dry ingredients to the pumpkin mixture. Stir gently just until no dry streaks remain.
Fold in about 1 cup of the chocolate chips, saving the rest for the top.
Spread batter into the pan, smooth the top, and sprinkle with remaining chips.
Bake 28–34 minutes, until a toothpick in the center comes out with a few moist crumbs.
Cool in the pan for 15 minutes, then cool completely on a rack. Slice and serve.