How to Make It
Preheat the oven to 450°F. Heat ¼ cup of the oil in a large skillet over medium-high. Add the sausage and break into small pieces. Cook, undisturbed, until browned, 8 minutes. Remove from heat.
Meanwhile, line two 8-by-13-inch baking sheets with parchment. Stretch 1 ball of the dough until it reaches the edges of a baking sheet. Brush with 2 tablespoons of the oil. Dimple the dough with your fingers. Repeat with the second ball. Bake both crusts for 5 to 7 minutes, until puffy and dry on top. Remove the crusts from the oven. Increase oven temperature to 500°F. Cool the crusts completely.
Divide the mozzarella between the 2 pizzas and dollop each with the marinara. Divide the sausage between the pizzas, along with the fennel, serrano peppers, Parmesan, and black pepper.
Bake on the bottom rack until the crust is brown and the top is bubbly, 10 to 12 minutes. Transfer to a cutting board and slice each pizza into 8 pieces.
How to freeze and reheat: Tightly wrap each sheet tray with 2 layers of plastic wrap and a layer of foil. Freeze for up to 1 month. Bake the pizzas directly from the freezer according to the recipe, adding 8 to 10 minutes to the cooking time.