Make the dough: In a small bowl, combine warm water and sugar. Sprinkle yeast on top and let sit for 5-10 minutes until frothy.
Combine dry ingredients: In a stand mixer, combine flour and salt. Add the yeast mixture and olive oil. Mix on low speed, then increase to medium and knead for 5-7 minutes until smooth and elastic. If sticky, add more flour.
First rise & fermentation: Place dough in a lightly oiled bowl, cover with a damp cloth, and let rise for 1 hour or until doubled. Punch down, divide in half, and shape into balls. Let rest at room temperature for 3 hours. For best results, refrigerate overnight or for 3-5 days.
Prepare the dough: Roll out dough on a floured surface to 12-14 inches and use a fork or docker to poke holes to prevent bubbles. Let sit at room temperature, uncovered, for 3 hours to cure and dry.
Make the sauce: Blend peeled tomatoes until smooth. In a small pot, heat olive oil over medium heat and cook garlic for 1 minute. Add blended tomatoes, tomato paste, oregano, sugar, red pepper flakes, salt, and pepper. Simmer for 20-30 minutes until thickened. Adjust seasoning.
Assemble the pizza: Preheat oven to 475°F, placing the pizza stone inside to heat for 45 minutes. Sprinkle cornmeal on the pizza peel. Transfer dough to the peel. Spread a thin layer of sauce, top with mozzarella, sausage, and pepperoncini. Sprinkle with pecorino romano.
Bake the pizza: Slide the pizza onto the preheated pizza stone and bake for 12-15 minutes, or until the crust is golden and cheese is bubbly. Remove from the oven, let rest, slice, and serve hot.