Preheat oven to 350 and line a large cookie sheet with parchment paper or a silicone baking mat.
In a large bowl mix together the flour, baking soda, cinnamon, ginger, nutmeg, allspice, cloves, salt, and oats. Set aside
In a medium bowl, whisk together the melted butter, molasses, brown sugar, sugar, egg yolk, pumpkin, and vanilla until combined.
Pour the wet ingredients into the dry and mix until combined. Stir in chocolate chips.
Scoop about 1 1/2 tablespoons dough (I use a medium cookie scoop) and place onto the prepared pan and flatten slightly.
Bake for 11-12 minutes. Cookies will be mostly set.
Let cookies cool for 3 minutes on the baking sheet before removing to a cooling rack to cool completely.
Notes
Pumpkin: Canned pumpkin is really soft and has a lot of water, it’s one of the things that makes pumpkin treats so moist, but all of the liquid is the enemy of a chewy cookie. So it is important that we remove some of the liquid from the pumpkin before adding to the recipe: 1. Measure out 3/4 cup pumpkin puree 2. Line a small bowl with a couple of layers of paper towels. Place pumpkin into the paper towel-lined bowl and cover with another layer of paper towels and squeeze out the excess water.Spices: You can sub the ginger, nutmeg, allspice, and cloves with 2 teaspoons pumpkin pie spice.Based on this recipe.