01 - Set oven to 350°F (180°C).
02 - Boil ramen noodles in unsalted water for 2 minutes less than package directions. Drain thoroughly and reserve.
03 - Warm vegetable oil in a large skillet over medium heat. Add onion, garlic, and ginger; cook until softened and fragrant, about 3 minutes.
04 - Add ground pork to skillet and cook until fully browned, breaking up pieces with a spoon.
05 - Incorporate gochujang, crushed red pepper flakes, crushed tomatoes, soy sauce, rice vinegar, and sugar. Season with salt and pepper. Simmer for 10 minutes until the sauce thickens slightly.
06 - In a mixing bowl, thoroughly blend ricotta cheese, egg, half the mozzarella, and half the parmesan.
07 - Spread a thin layer of meat sauce across the bottom of a 9x13-inch (22x30 cm) baking dish.
08 - Arrange a layer of ramen noodles, using approximately one pack, trimming if needed to fit evenly.
09 - Spread one third of the ricotta mixture over noodles, followed by one third of the meat sauce. Repeat to create three total layers, finishing with the remaining meat sauce.
10 - Sprinkle remaining mozzarella and parmesan evenly over the top.
11 - Cover dish securely with aluminum foil. Bake for 20 minutes, then remove foil and continue baking 10–15 minutes until cheese is bubbling and lightly golden.
12 - Allow to rest for 10 minutes before slicing. Garnish with green onions if desired and serve.