Mix flour, water, olive oil, yeast, salt, and sugar together in a large bowl. Use an ice cream scoop to place 12 balls of dough onto the prepared pan, patting down slightly; dough will be very sticky. Let sit until risen, about 30 minutes, without kneading or punching down. Preheat the oven to 425 degrees F (220 degrees C). Grease a baking pan. Toss an ice cube into the bottom of the oven to add some humidity. Combine tomato sauce, garlic, oregano, and basil in a bowl. Add olive oil, vinegar, and sugar; stir very well. Spread 1 to 2 tablespoons tomato sauce on each dough ball. Sprinkle 1 to 4 tablespoons mozzarella cheese on top and add spinach. Bake in the preheated oven for 15 minutes. Let cool slightly before serving.