Preheat your oven to 350°F and line a 9-inch pie pan with parchment paper. Set it aside.

In a large mixing bowl, beat together the softened butter, brown sugar, and granulated sugar using a hand mixer until the mixture becomes light and fluffy.

Add the pumpkin puree, vanilla extract, and egg to the butter mixture. Beat again until everything is well combined. If you want to add orange food coloring, this is the time to do it—just add a few drops until you reach your desired color.

In a separate medium-sized bowl, whisk together the flour, baking soda, cinnamon, and salt. Gradually add the dry ingredients to the wet ingredients, about ½ cup at a time, mixing until a wet dough forms.

Gently fold in the chocolate chips, mini marshmallows, and graham cracker bits using a silicone spatula. Mix until everything is evenly distributed and not clumped together.

Transfer the dough to the prepared pie pan and spread it out evenly. For an extra touch, you can sprinkle additional chocolate chips, mini marshmallows, and graham cracker bits on top before baking.

Bake in the preheated oven for 20-25 minutes, or until the edges are golden brown and the marshmallows have a nice golden color.

Once baked, let the cookie cake cool in the pan for about 20 minutes. Then, use the parchment paper to lift the cookie cake out of the pan. Slice, serve, and enjoy!