1. Measure 1/2 cup pumpkin purée and then place in a cheesecloth or towel to squeeze out all excess water. Set aside.
2. In a large bowl, mix together softened butter and sugars until combined.
3. Add in the prepared pumpkin purée, eggs, and vanilla extract to the wet ingredients, mixing well.
4. In a separate bowl, combine all dry ingredients: flour, 1 tsp cinnamon, nutmeg, all spice, baking soda, and cream of tartar.
5. Slowly begin incorporating the dry ingredients into the wet ingredients until a sticky dough forms.
6. Refrigerate the dough for 2-3 hours to allow it to harden and become easier to handle.
7. Prepare the cinnamon sugar coating by combining 1/4 cup granulated sugar and 1 Tbsp cinnamon in a shallow bowl.
8. Once the dough is chilled, form cookie dough balls and toss them into the cinnamon sugar mixture to coat.
9. Place the coated cookie dough balls on a parchment-lined baking sheet, leaving plenty of room between them as they will expand.
10. Gently press down on each cookie ball to flatten it slightly before baking.
11. Preheat oven to 350°F (175°C).
12. Bake for approximately 10-12 minutes. Do not overbake if you desire a chewy center, as cookies will continue to set as they cool.
