In a large bowl, whisk the melted butter and brown sugar together until smooth.
½ cup unsalted butter, ¾ cup brown sugar
Add the pumpkin puree, egg, and vanilla and whisk to combine.
¼ cup pumpkin puree, 1 large egg, 1 teaspoon pure vanilla extract
Add the flour, baking soda, and pumpkin pie spice and mix them in gently-- just until no large lumps of flour remain.
1½ cups all-purpose flour, 1 teaspoon baking soda, ½ teaspoon pumpkin pie spice
Gently fold in the chocolate chips.
½ cup chocolate chips
Transfer the dough to the refrigerator to chill for 30 minutes.
While the dough chills, preheat oven to 350°F and line 2 baking sheets with parchment paper.
Once the dough has chilled, scoop 2-tablespoon-sized balls onto the baking sheets, making sure to place them at least 2 inches apart-- these cookies will spread!
Bake for 15-18 minutes or until the cookies are set around the edges and golden brown on the bottom.
Allow the cookies to cool on the pan-- they will set as they cool.