01 - Set oven to 350°F (180°C) and allow to preheat fully.
02 - Cook ramen noodles in boiling water for 2 minutes less than package directions. Drain and set aside.
03 - Heat vegetable oil in a large skillet over medium heat. Add onion, garlic, and ginger; cook until fragrant and translucent, about 3 minutes.
04 - Add ground pork to the skillet. Sauté until thoroughly browned, breaking up the meat as it cooks.
05 - Stir in gochujang, red pepper flakes, crushed tomatoes, soy sauce, rice vinegar, and sugar. Season with salt and pepper. Simmer for 10 minutes, allowing the mixture to thicken slightly.
06 - In a mixing bowl, blend ricotta cheese, egg, half the shredded mozzarella, and half the grated parmesan until smooth.
07 - In a 9x13-inch baking dish, spread a thin layer of meat sauce. Arrange a layer of ramen noodles, fitting to cover the surface. Top with one-third of the ricotta mixture, followed by one-third of the meat sauce. Repeat layering twice, finishing with meat sauce on top.
08 - Sprinkle remaining mozzarella and parmesan cheese evenly over the top layer.
09 - Cover dish with aluminum foil and bake for 20 minutes.
10 - Remove foil and continue baking for 10–15 minutes, until cheese is bubbling and lightly golden.
11 - Let stand for 10 minutes before slicing. Garnish with green onions if desired.