Mix yeast and water, let stand for 10 minutes. Add flour and salt, stir with a wooden spoon for 2 minutes to form soft dough. Cover and let rise in a cool spot until doubled in size, 8-12 hours.

Deflate and de-gas the dough using a wet hand. Form into a ball, cover, and store in the refrigerator until needed.

Preheat oven to 400°F (200°C). Pierce sweet potatoes and place on a baking sheet. Roast until soft, about 1 hour. Let cool for 10 minutes.

Scoop sweet potato flesh into a bowl, mash with seasonings including salt, black pepper, cayenne, olive oil, rosemary, lemon zest, lemon juice, and Parmigiano Reggiano cheese. Taste and set aside.

Cook bacon in a cold, dry nonstick skillet over medium-high heat until almost crisp, 7-10 minutes. Drain on paper towels.

Preheat oven to 450°F (235°C). Spread olive oil on baking sheet, press dough into the pan's edges using oiled hands. Let dough rest if very elastic. Stretch until pan is covered.

Spread sweet potato mixture onto dough, followed by mozzarella, bacon, fontina, jalapeños, and dusting of Parmigiano Reggiano cheese.