In the bowl of a stand mixer, combine the gluten-free flour, granulated sugar, instant yeast and salt. Mix to combine.
With the mixer running on low, slowly add the water and oil. Increase the speed to medium-high and beat for 5 minutes.
Using an oiled spatula, scoop the dough into a medium-sized oiled bowl. (I rub a tablespoon of oil on the sides/bottom of the bowl so the dough doesn’t stick while it rises.)
Cover and let rise in a warm spot for 1 to 1 ½ hours, until doubled in size.
Meanwhile, place a pizza stone in the oven and preheat the oven to 475F. Let the pizza stone preheat for at least 20 minutes.
Spray a large piece of parchment paper (about the size of a baking sheet) with cooking spray. Using oiled or wet hands, press the dough into a long rectangle that is ⅓ inch thick. Let rise for another 10 minutes.
Slide the parchment paper on the pizza stone and bake for 10-15 minutes. Mix together the melted butter and garlic salt. Remove the parchment paper/dough from the oven and spread the melted butter/garlic salt over the dough. Sprinkle the mozzarella/parmesan cheese over the top.
Slide the dough off the parchment paper onto the baking stone and cook for another 5-10 minutes, until golden brown and crisp on the bottom.
Let cool for 5 minutes then slice in half the long way, and then into 1 to 1 ½ inch strips.
Serve with marinara sauce for dipping if desired. Enjoy!