Dough: Combine warm water, sugar and yeast in the bowl of a stand mixer and combine. Let sit for 5-10 minutes until mixture begins to get foamy. Add the olive oil and combine. Mix the flour and salt in a medium bowl; add to the the mixer and with the dough hook attached beat until the dough forms into a ball.

Scrape dough onto a lightly floured surface and knead gently. Form into two even balls. Transfer to two bowls sprayed with non-stick cooking spray. Cover with plastic wrap and let rise in a warm placed until doubled in size, 1-2 hours.

Sauce: Place tomatoes in a strainer. Squeeze tomatoes carefully because juice will squirt out and leave in strainer for 20 minutes. Then place tomatoes, garlic, oregano, salt, red pepper flakes and sugar in a blender and blend until smooth. Some slight chunks are ok too.

Preheat oven to 500 degrees. If you are using a pizza stone place that in the oven to preheat also.

Toppings: Remove sausage from casing and cook, in a large skillet over medium-high heat breaking into medium chunks until no longer pink. Remove from skillet and set aside.

Heat one tablespoon olive oil in medium skillet over medium-high heat. Add onion and cook for 3-4 minutes until softened. Remove from skillet and set aside.

Assembling pizza: Stretch one ball of dough into a 12 inch round on a lightly floured and cornmealed pizza peel or rimless baking sheet. Spread 1/3-1/2 cup sauce on top of the dough, leaving a 1/2 inch border. Sprinkle with 1/2 of the cheese, sausage, onion and peppers. Drizzle lightly with olive oil and then sprinkle with red pepper flakes and fennel seed. Slide the pizza onto the stone if you're using or baking sheet and bake until the crust is golden brown and the cheese is bubbly, about 10-15 minutes, rotating if needed.

Remove from oven and sprinkle with oregano leaves and parmesan cheese if desired. Transfer to a cutting board and let cool 2 minutes before cutting into slices. Repeat with second ball of dough.