Preheat your oven to 350°F. Line rimmed baking sheets with parchment paper and set them aside.

In a medium-size bowl, place the maple syrup, pumpkin butter, melted butter, egg and egg yolk, and vanilla, whisk together vigorously until smooth and well-combined. Set the wet ingredients aside.

In a large mixing bowl, place the flour, xanthan gum, baking soda, salt, pumpkin pie spice, and granulated sugar, and whisk to combine well. Add the oats, and mix to combine.

Create a well in the center of the dry ingredients and add the pumpkin and butter mixture. Mix until just combined.

Add the chocolate pieces, and mix again just until the pieces are evenly distributed throughout the cookie dough.

Using a spring-loaded ice cream scoop or two spoons, scoop the dough in portions of about 2 tablespoons each and place them about 2 inches apart on the prepared baking sheets. They will spread quite a bit during baking.

Using wet fingers, press each mound of dough with the tips of your fingers to flatten it into a disk about 3/4-inch thick.

Place the baking sheet in the center of the preheated oven, and bake for about 14 minutes, or until lightly golden brown all over, and a bit browner around the edges. The cookies will still be soft to the touch.

Remove the baking sheet from the oven, and allow the cookies to cool on the baking sheet until firm (about 10 minutes) before transferring to a wire rack to cool completely.

Repeat with the remaining cookie dough.