Preheat the oven to 350 degrees F. Spray a 9×13 inch pan with nonstick spray, or line with parchment paper.
In a medium saucepan, melt 1 cup of butter over medium heat.
When the butter is still bubbly and hot, add in 1 tablespoon pumpkin pie spice. Let the spices toast in the pan for just a few seconds, then remove the pan from heat.
Stir in 1 cup sugar and 1 cup packed brown sugar.
Add in 1 cup pumpkin puree from a can.
Add 2 teaspoons vanilla and ½ teaspoon kosher salt.
Add 1 egg and stir vigorously right away.
Add 2 cups flour, but don’t stir yet. Add 1 teaspoon baking powder to the flour and stir it into the flour.
Stir in the flour until most of the lumps are gone, but do not over beat.
Pour the batter into the prepared pan and spread to the edges.
Sprinkle 1 cup semisweet and 1 cup dark chocolate chips over the top. Gently fold them in.
Bake at 350 for about 25-30 minutes. They are done when a toothpick inserted in the center comes out with no wet batter on it.
Let cool before lifting the paper from the pan and slicing.
