Preheat your oven to 350°F (180°C). Line a 9x9 inch baking pan with parchment paper, leaving some overhang on the sides for easy removal.
In a large bowl, mix together brown sugar, granulated sugar, melted butter, egg, and pumpkin puree until well combined.
½ cup brown sugar, ¼ cup granulated sugar, ⅓ cup butter, 1 egg, ½ cup pumpkin puree
Add all-purpose flour, baking soda, pumpkin spice, and salt directly to the wet ingredients in the same bowl. Mix until just combined.
1 ¼ cups all-purpose flour, ½ teaspoon baking soda, 1 teaspoon pumpkin spice, ¼ teaspoon salt
Fold in chopped chocolate or chocolate chips, reserving a small amount to sprinkle on top.
1 cup chopped chocolate
Pour the batter into the prepared baking pan and spread it evenly. Sprinkle the reserved chopped chocolate on top.
Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Let the pumpkin bars cool completely in the pan on a wire rack.
Once cooled, use the overhanging parchment paper to lift the pumpkin bars out of the pan. Cut into squares and serve.