Fill a pot with water and set it over high heat to boil. Add the ramen noodles and cook according to package instructions. Save at least 1/4 cup of the pasta water!
Add the butter to a pan over medium heat. When the butter melts, add the miso paste and stir until a thick paste has formed. Add a splash of pasta water and stir until a smooth sauce is achieved.
Transfer the hot ramen noodles into the pan. Add parmesan and black pepper and toss until well combined. If needed, add another splash of pasta water to help everything come together so you have silky smooth noodles.
Transfer to a bowl and top with more parmesan and pepper. Enjoy while it's hot!