COOK PASTA: Place a large saucepan on high heat and add hot water. Bring the water to a boil then season with salt and add the bucatini.
Cook the bucatini for 8 minutes then strain through a colander, reserving one cup of pasta water.
MAKE SAUCE: In a second saucepan on medium heat add half of the butter. Once melted, stir in the black pepper and allow to toast for 1 minute. Then add half a cup of pasta water and bring to a simmer, stir in the remaining butter.
ADD PASTA: Reduce the heat to low then toss the cooked bucatini, pecorino and parmesan through the sauce. Stir to melt the cheese and form a thick silky sauce, add pasta water gradually if the sauce becomes too dry.
SERVE: Serve the bucatini cacio e pepe immediately into warm bowls with an extra crack of fresh black pepper and grating of parmesan cheese.