If making the spinach-cheese filling, steam the spinach in a large covered pot filled with 1/2 inch of water. Turn the heat to medium high and cover the pot until the spinach is wilted. Drain the spinach, then return to the pot. Stir the cheese into the hot spinach and mix well. Set aside.
Oil a deep dish pizza pan or large dark colored cake pan (9-10 inches or larger) or springform pan, ideally (makes the pizza easier to cut and remove). Sprinkle cornmeal evenly across the bottom after oiling.
Make the homemade gluten-free pizza dough using my from-scratch recipe or my gfJules Gluten Free Pizza Crust Mix.
After making the pizza dough, separate it into two: one contains 2/3 of the dough, one contains 1/3 of the dough. From the dough, scoop out smaller pieces to arrange on the bottom and sides of the prepared pan.
Using your hands (rub lots of oil between your hands before touching the sticky dough), press the dough pieces together across the bottom of the pan and up the sides of the pan with your palms (or use oiled plastic wrap). The dough should cover the bottom and sides with an even thickness, and if possible, lay up and over the outside top edge of the pan. Remember – it doesn’t matter how messy or haphazard the dough looks to you at this point, just try to get it to a fairly even thickness.
Spread your favorite pizza toppings or the wilted spinach and cheese evenly across the dough, coming all the way to the edge of the pan where the dough begins to go up the sides.
Dust a piece of parchment or a silicone baking mat and rolling pin well with gfJules All Purpose Gluten Free Flour. Place the remaining pizza dough in the center of the floured mat and dust with more flour. Lay a piece of parchment or plastic wrap on top and begin to gently roll the dough out in all directions, adding more flour if necessary to keep the dough from sticking (or use a rolling pin cover or pie crust bag).
Once the dough is rolled to the diameter of your pan, the dough is ready to lift and top the other crust. Place one hand on top of the covered, rolled out dough, and another underneath the mat to flip the crust onto the parchment or plastic wrap side, then flip back on top of the stuffed pizza.
Peel off the parchment or plastic wrap – don’t worry if it sticks or rips at all, just press it back into place once the parchment or wrap is removed. Remember, this crust will be covered too, so no one will see any blemishes in the crust even if you have to patch it back together!
Press the edges of the two crusts together and pinch. Wet the crusts lightly if they are not sticking together because the top one is floured.
Cover with parchment and place it in a warm spot to rise for 20 minutes (an oven set to 200°F then turned off is a good place).
Preheat oven to 500°F.
Brush oil on top of the crust. Remove parchment and bake pizza for 5 minutes on low-middle rack.
Spread pizza sauce and any toppings on top of the second crust and return to the oven to bake another 12-15 minutes, covering edges with foil if they are browning too much.