Preheat your oven to 350°F and line two baking sheets with parchment paper.
The first step is to remove excess moisture from the pumpkin puree. You can do this by either placing the puree on paper towels and letting them soak up the liquid for a few minutes, or by using a clean kitchen towel to gently squeeze out the moisture (just be careful, it can stain). You should end up with about ½-¾ cup of pumpkin puree.
In a medium bowl, whisk together the flour, pumpkin pie spice, baking soda, and salt.
In a large bowl, cream the butter and brown sugar with an electric mixer until light and fluffy, about 1-2 minutes. Add the egg and vanilla and mix until pale and fluffy. Mix in the dried pumpkin.
Add the dry ingredients to the wet ingredients and stir gently until just combined.
Scoop the dough into 2-tablespoon-sized balls and roll them in a bowl of sugar. Place the dough balls at least 2 inches apart on the baking sheets.
Bake the cookies for 13-15 minutes until the edges are set. Remove from the oven and allow to cook in the pan for 5 minutes before transferring to a wire rack to cool completely.
Nutrition information is calculated using an ingredient database and should be considered an estimate.