1. Preheat oven to 425ºF; prepare dough as package label directs.
2. Warm oil in a medium pan over medium-high heat. Add onion and salt; sauté until onion has softened, about 3 minutes. Reduce heat to low; stir in tomato puree, sugar, oregano and pepper. Simmer for 10 minutes.
3. Mist 2 pizza pans or round baking sheets with gluten-free cooking spray. Divide dough in half; spread on pans. Pour sauce over each, leaving 1/2-inch border. Sprinkle with mozzarella. Try arranging pepper slices in a pinwheel pattern. Place olive halves between pepper slices. Bake for 15 to 18 minutes (or as package label directs), until crust is light golden and cheese has melted. Allow to cool for 5 minutes. Top with basil leaves just before serving.