Preheat your oven to 375°F (190°C). Spread a thin layer of meat sauce on the bottom of a 9x13-inch baking dish. Layer 3 lasagna noodles on top. Add half of the ricotta mixture, followed by a third of the meat sauce, and sprinkle with mozzarella cheese. Repeat with the remaining noodles, ricotta, meat sauce, and mozzarella.