Bring a large pot of salted water to a boil. Cook pasta and drain 1 minute before the time indicated on the package instructions.
In a mixing bowl, combine truffle mayo, milk, and 2 cups of the cheese. Check the consistency of the sauce as it should be a liquid cream sauce. Add more milk if needed.
Once consistency looks good, add in the pasta and stir to fully coat the pasta in the cream sauce.
Pour pasta into a baking dish, and top with the remaining cheese.
Bake until pasta is fully cooked (about 35 minutes)