Lasagna Casserole

Instructions

• Preheat the oven to 375 degrees F (190 degrees C). Set a rack in the center of the oven, about 10 inches from the heat source.
• Bring a large pot of salted water to a boil. Add shells and cook, stirring occasionally, until almost tender, about 7 minutes. Drain pasta in a colander. Return to pot and toss with 1 tablespoon oil.
• Meanwhile, heat remaining 3 tablespoons oil in a large Dutch oven over medium-high heat. Add sirloin and sausage and cook, undisturbed, until bottom side is lightly browned, about 6 minutes. Stir, and continue to cook, stirring and breaking up meat into smaller pieces with a wooden spoon, until cooked through, about 4 minutes.
• Reduce heat to medium. Add onion and garlic, and cook, stirring often, until softened, about 4 minutes.
• Stir in marinara sauce, basil, and crushed red pepper. Remove ragu from heat.
• Stir together ricotta, Parmigiano-Reggiano, cream, and salt in a bowl.
• To assemble, spread about 2 cups of the ragu in the bottom of a 13- x 9-inch baking dish. Spoon 1/2 of the pasta over sauce. Dollop half of the ricotta mixture over pasta, and sprinkle with 1 cup mozzarella cheese. Spoon remaining pasta over mozzarella cheese. Spread remaining ragu over pasta mixture, and dollop with remaining ricotta mixture. Top with remaining 1/2 cup mozzarella cheese. Cover lasagna with a large sheet of aluminum foil that's been lightly sprayed with cooking spray (to prevent the cheese from sticking to it).
• Bake in preheated oven for 30 minutes. Remove from oven and remove foil. Increase oven temperature to broil with rack about 10 inches from heat source; preheat 5 minutes. Return baking dish to oven. Broil until cheese is browned in spots, 5 to 8 minutes.