Preheat oven to 350 °F (177 °C). Line a large baking sheet with parchment paper or spray with non-stick baking spray or use a silicone baking mat. Set aside.
In a medium bowl, whisk together flour, baking soda, pumpkin pie spice, and salt. Set aside.
In a large mixer bowl, beat together the butter and sugars (brown & white) until light and creamy.
Add in the pumpkin, egg, and vanilla extract and mix together until well combined.
Gradually add in the dry ingredients and mix until all is combined in a thick batter.
Fold in the oats, chocolate chips, and dried cranberries. You're gonna need some elbow grease here! It's a very thick batter once everything is added in!
Drop cookies onto baking sheet in rounded tablespoons, about 2 inches apart.
Bake for 12-14 minutes until the cookies are lightly browned.
Let cool on baking sheet for 3-5 minutes then transfer them to a wire rack to cool completely. Store in an airtight container for up to 5 days.