Bring a large pot of salted water to a boil. Add the spaghetti and cook until al dente, following package instructions. Remember to reserve about 1 cup of pasta water before draining.

In a large skillet over medium heat, melt 2 tablespoons of butter. Once melted, add the freshly ground black pepper and cook for about a minute to release its flavors.

Pour about ½ cup of the reserved pasta water into the skillet. Add the drained spaghetti along with the remaining tablespoon of butter. Toss everything together to coat the pasta evenly.

Reduce the heat to low. Gradually add the finely grated Pecorino Romano cheese while stirring continuously. Continue until a creamy sauce forms, adjusting the consistency with more pasta water if needed.

Serve immediately, garnished with extra cheese and freshly ground pepper if desired.