In a large bowl mix together 2 cups of bread flour, sugar, salt, corn oil, and Fleischmann’s® RapidRise® Instant Yeast.
Make a well in the center of the dry ingredients and add the warm water. Using your hands, mix everything together until it forms a dough. The dough will be sticky, but don’t worry, it will come together once you knead it!
Turn the dough out onto a floured surface and knead the dough for 5 minutes or until the texture of the dough starts to smooth out. If the dough feels too sticky, add the remaining ¼ cup flour (a tablespoon at a time) until the dough is dry enough to work with. Form the dough into a smooth ball and place in a greased bowl. Cover loosely with a dish cloth and set in a warm place to rise for 30 minutes.
While the dough is rising, place a pizza stone in the oven and preheat the oven to 500°F.
While the oven is preheating, place the pepper, mushrooms, onion, and sausage in a saucepan over medium heat and cook until tender and sausage is cooked. Set aside.
After the dough has rested for 30 minutes, turn it out onto a clean work surface to shape the dough. Doing this on a piece of parchment paper allows for easy cleanup and transport of the shaped dough. Stretch out dough to form a 12-inch round.
Spoon the marinara sauce into the center of the pizza. Using the back of a spoon, spread the sauce out from the middle, leaving about 1 inch of crust around the edges. Sprinkle with the shredded cheese and top with the onions, peppers, mushrooms and sausage. Using oven mitts, carefully take the hot pizza stone out of the oven and transfer the pizza (on the parchment paper, if using) onto the pizza stone, place into the oven and bake for 10 minutes, rotating halfway through for even browning. Take out when the crust is golden brown and the cheese is bubbling.