Heat your oven to 350°F and line your baking pan with parchment paper with some hanging over the sides.
Mix pumpkin, melted butter, brown sugar, eggs, and vanilla together until everything looks smooth and well combined.
Whisk flour, pumpkin pie spice, baking powder, and salt together in a different bowl until evenly mixed throughout.
Fold dry ingredients into wet mixture gently, stirring just until combined without mixing too much or overworking the batter.
Stir in most of the chocolate chips and save some to sprinkle on top for a pretty bakery look.
Pour batter into your prepared pan, spread it evenly, then sprinkle those reserved chocolate chips all over the top.
Bake for 25-30 minutes until edges look set and a toothpick poked in comes out mostly clean.
Cool completely in the pan for 1hr, then lift out using the parchment paper and slice into DELICIOUS bars!