Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.
In a medium bowl, whisk together the flour, oats, cinnamon, pumpkin pie spice, baking soda, and salt.
In a large bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy.
Beat in the egg, pumpkin purée, and vanilla extract until well incorporated.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the semi-sweet chocolate chips by hand.
Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them 2 inches apart.
Bake for 10 to 12 minutes, or until the edges are firm and slightly golden.
Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.