Preheat the oven to 350°. In a small bowl, combine the gluten free 1:1 baking flour, unsweetened cocoa powder, pumpkin spice, baking soda, and salt with a whisk. In a medium bowl, mix together the pumpkin puree, maple syrup, and applesauce. Combine the dry ingredients with the wet ingredients from step 3 until the batter is smooth. Pour the batter into an 8-iinch square glass or metal baking pan coated with cooking spray. Sprinkle the dark chocolate chunks over the top of the batter. Bake for 20 minutes, or until an inserted toothpick comes out with a few crumbs on it. If the toothpick is clean, it's overcooked! Cool for 15 minutes before slicing. Enjoy!