Upside-down focaccia with pepperoni and cheese

Ingredients:

• 6 cups premium flour + extra for work
• 1.5 tbsp. sugar
• 3 teaspoons coarse salt
• 2 tsp active dry yeast
• 2.5 cups warm water (about 40°C)
• 0.5 cup + 3 tablespoons extra-virgin olive oil + extra for greasing the pan, bowl, hands, and dough
• 150 g pepperoni (about 65 thin slices)
• 2 tsp dried oregano
• 450 gr. grated mozzarella
• Any marinara sauce, heat up, for serving

Preparation:

1. Place the flour, sugar, salt, and yeast in the bowl of a stand mixer fitted with a dough hook. In a liquid measuring cup, combine the warm water with 3 tablespoons of olive oil. Turn the mixer on low speed and add the liquid mixture to the flour mixture. Knead until a loose dough forms, about 1-2 minutes. Alternatively, knead the dough by hand: combine the dry ingredients in a large bowl. Make a well in the center, then add the warm water and olive oil and mix with a wooden spoon.
2. Increase the mixer speed to medium and knead the dough until smooth and slightly sticky, about 7 minutes. If kneading by hand, form the dough into a ball, turn it out onto a floured surface, and knead, dusting your hands and the countertop with flour as needed, for about 5 minutes.
3. Pour 2 tablespoons olive oil into a large bowl and use your hands to coat the entire inside surface. Pour the remaining 1/3 cup plus 1 tablespoon olive oil into a 10 x 17-inch baking sheet and spread it evenly over the surface. Arrange the pepperoni slices in a single layer on the bottom of the greased baking sheet, then sprinkle the dried oregano evenly over the pepperoni. Using your olive oil-oiled hands, divide the dough in half, placing half in the greased bowl and turning once to coat. Place the other half of the dough on the prepared baking sheet, gently spreading it with your hands. The dough will not completely cover the pepperoni at this point; you will stretch it out later. Dip a pastry brush into the oil on the baking sheet and brush the surface of the dough with oil. Cover both the baking sheet and the bowl of dough loosely with plastic wrap and let rise in a warm place until the dough fills about two-thirds of the baking sheet and the dough in the bowl has doubled in size, 1 to 1 1/2 hours.
4. Remove the plastic wrap from the baking sheet and bowl. Using your hands, gently press and stretch the dough to completely cover the bottom of the baking sheet, keeping the pepperoni slices in a single layer. Sprinkle the dough with an even layer of mozzarella. Using oiled hands, remove the dough from the bowl, stretch it, and gently press it into an even layer on top of the mozzarella. Pour the remaining oil from the bowl over the dough and spread it with a brush. Cover loosely with plastic wrap and let rise in a warm place for 1 to 1.5 hours.
5. Meanwhile, position a rack in the middle of the oven and preheat the oven to 260°C.
6. Bake the pizza until golden brown and pulling away from the sides of the pan, and the oil is bubbly around the edges, 15-20 minutes. Remove the pizza from the oven. Let it cool for a few minutes, then invert it onto a cutting board. Cut the pizza into squares and serve with warm marinara sauce for dipping.