Bring a large pot of water to a boil. Add a pinch of salt and the spaghetti. Cook, stirring occasionally, until al dente, about 9 minutes.

While the pasta cooks, heat a large skillet over medium heat. Add the black pepper and toast until fragrant, about 1 minute.

Add 2 tablespoons of pasta water to the skillet with the pepper, then add the butter. Stir until the butter melts and the sauce is creamy.

Drain the spaghetti and add it to the skillet. Toss with the sauce to coat.

Remove the skillet from heat. Add the grated Pecorino Romano cheese and toss until the cheese melts and the sauce coats the spaghetti evenly.

Serve immediately, topped with additional grated cheese and black pepper to taste.