Preheat the oven to 350F (180C) degrees. Line cookie sheets with parchment paper or silicone baking mats.
Place a paper towel in a small bowl. Add in the pumpkin and squeeze out the excess liquid with the paper towel. Set aside to use later.
In a medium bowl, whisk together the flour, cinnamon, ginger, nutmeg, coves, baking soda and salt.
In a large bowl, beat together the butter, brown sugar and white sugar until fluffy.
Mix in the blotted pumpkin puree, egg yolk, and vanilla extract until evenly mixed.
With the mixer on a low speed, mix the flour mixture into the butter mixture until no lumps remain.
Stir in the oats. Note that the mixture will be sticky.
Stir in the chocolate chips.
Spoon the cookie dough into balls with about 1 ½ tablespoons of dough each. Place 2 inches apart on the lined cookie sheets and flatten them down slightly. If the dough is too sticky, cover the bowl with plastic wrap and refrigerate for 30 minutes or overnight.
Bake 1 cookie sheet at a time in the middle of the oven. Bake the cookies for 10-12 minutes, or until the tops look set. Cool on the cookie sheet for at least 10 minutes. Optionally, dot a few extra chocolate chips on top of each cookie.