In a stand-mixer bowl, with a hook attachment, add yeast, water and sugar and whisk with a fork. Allow the mixture to sit for about 5-7 minutes until frothy. Add the salt and extra virgin olive oil.
At a low speed, gradually add the flour to the yeast mixture, 1 cup at a time, mixing well between additions. Continue adding the flour until the dough starts pulling away from the sides of the bowl and forms into a ball. Remove from the bowl and knead by hand for about 5 minutes.
Grease a large size bowl with olive oil and place the dough into the bowl, turning it so it is coated with olive oil, and cover it with plastic wrap or a towel, and set it in a warm place, without any drafts for about 45 minutes, until the dough has doubled in size.
While the dough is rising, using a skillet over medium heat, fry bacon until slightly cripsy, then sauté the onions in the same skillet, until it starts to become golden and caramelize about 30 minutes, transfer to a plate. Add garlic and spinach and cook for 2 minutes, remove from heat.
Preheat oven to 450°F (230C). Spread tomato sauce over dough, then start adding toppings, caramelized onions, spinach, bacon, red pepper flakes is you like, brie, mozzarella and Parmesan cheese. Bake for 20 minutes.
Serve with fresh basil and drizzle with olive oil. Enjoy!
