In a bowl, combine the sliced beef, soy sauce, sesame oil, gochujang, garlic powder, ginger powder, salt, and pepper. Marinate for at least 30 minutes.

Heat vegetable oil in a skillet over medium-high heat. Add the marinated beef and cook for about 3-4 minutes until browned and cooked through. Remove from heat and set aside.

In a large pot, bring the beef broth and water to a boil. Stir in the miso paste, rice vinegar, and sugar until dissolved.

Add the ramen noodles to the boiling broth and cook according to package instructions, usually about 3-4 minutes.

Once the noodles are cooked, reduce the heat and stir in the heavy cream. Allow to simmer for an additional 2 minutes.

Serve the ramen in bowls, topped with the grilled beef, chopped green onion, and a sprinkle of sesame seeds.