Prepare the Dough:

• In a bowl, mix the warm water, sugar, and yeast. Let it sit for about 5 minutes until it becomes foamy.
• In a separate bowl, combine flour and salt. Add the yeast mixture and olive oil, and stir until the dough forms. Knead the dough on a floured surface for about 5-7 minutes until smooth.
• Form the dough into a ball, place it in a greased bowl, cover with a damp cloth, and let it rise for about 1-1.5 hours, or until doubled in size.

Make the Sauce:

• In a saucepan, heat olive oil over medium heat. Add the onion and garlic, and sauté until softened.
• Add the crushed tomatoes, tomato paste, oregano, sugar, salt, and pepper. Simmer for 20-25 minutes, stirring occasionally, until the sauce thickens. Remove from heat and set aside.

Prepare the Filling:

• In a skillet, cook the sausage over medium heat until browned and fully cooked. Drain excess fat. If you’re using additional vegetables like bell peppers, mushrooms, or olives, sauté them in the same pan until softened.

Assemble the Pizza:

• Preheat your oven to 425°F (220°C).
• Roll out the dough on a floured surface into a large circle, big enough to fit a 9-inch or 10-inch deep dish pan.
• Grease the pan and sprinkle with cornmeal. Press the dough into the pan, making sure to cover the sides and base.
• Spread a layer of mozzarella cheese on the bottom of the crust. Add the cooked sausage and any other vegetables. Pour the tomato sauce over the filling, and sprinkle with grated Parmesan cheese.

Bake the Pizza:

• Place the pizza in the preheated oven and bake for 35-40 minutes or until the crust is golden brown and the cheese is bubbling.
• Let the pizza cool for 5 minutes before slicing. Garnish with fresh basil leaves if desired.