Preheat oven to 325℉ and line an 8x8 pan with parchment paper.
In a stand mixer, cream together the coconut oil and sugar until creamy. Add in the powdered sugar and vanilla until well combined.
Mix in the flour and cinnamon. Add in your water 1 teaspoon at a time until you have a shortbread dough that sticks together and can be pressed into the pan. The amount of water will vary depending on which gluten-free flour you use. Every gluten-free flour seems to need a slightly different amount of water!
Press half of the dough into the prepared pan.
Begin sprinkling the chocolate chips over the dough and alternating with tablespoon-sized amounts of marshmallow fluff across the dough. This can be very random, it's all going to melt together anyways!
On a piece of parchment paper, press the remaining ½ of the dough into a flat square the size of your pan. Flip this large piece of dough over the top of the chocolate/marshmallow filling and peel the parchment paper away. It's okay if it breaks a bit, just use your fingers to mend the dough together so that it completely covers the filling.
Bake for about 35-39 minutes, or until golden brown on the edges. Time may vary depending on your oven. Let cool completely.
In a separate bowl, mix together the icing ingredients, adding water 1 teaspoon at a time until you have a consistency you like. Spread the icing over the cooled squares and allow to harden before slicing and enjoying!
