Melt the butter (either in the microwave, covered, for 45 seconds, or in a saucepan on the stove over low heat for about five minutes).

Pour the melted butter into a large mixing bowl or stand mixer. Mix the white sugar and brown sugar into the melted butter. Make sure all the lumps of sugar have dissolved before continuing.

Add the egg yolk and mix well.

Add the vanilla and canned pumpkin. Mix well.

Add the salt, cinnamon, ginger, cloves, nutmeg, and allspice. Mix well.

Add 1/2 cup of the flour along with the 3/4 teaspoon of baking soda. Mix well.

Add the remaining one cup of flour and blend just until the flour disappears. 

Add the oatmeal and mix until it is evenly distributed throughout the dough. The dough will be sticky.

Cover and refrigerate for at least an hour.

When ready to bake, heat your oven to 350 degrees F.

Line baking sheets with parchment paper or silicone baking mats. Use a large cookie scoop and place the dough two inches apart on the baking sheets. While cookies are waiting to bake, place the cookie sheet in the refrigerator to keep the dough chilled.

Bake for 9-12 minutes, until edges just begin to brown. Allow cookies to remain on cookie sheets for about two minutes once removed from the oven. Then transfer to a wire rack to cool completely.