Warm a large frying pan over medium-low heat, then add the oil and minced garlic.
Sauté the garlic until it's soft and fragrant, about 3 minutes.
Meanwhile, bring salted water to a boil for the pasta.
Add the sliced mushrooms to the pan, cooking until they start to brown, around 5 minutes.
Sprinkle in 1 teaspoon of salt and sauté for an additional minute.
Once the water is boiling, add the pasta to cook. In the mushroom pan, add the butter and sauté until it melts.
Pour in the heavy cream and let it simmer with the mushrooms for 4 minutes, gradually stirring in the Parmesan cheese until fully melted and incorporated.
Set aside 1/4 cup of the pasta water before draining the cooked pasta.
Add the pasta water and drained pasta to the sauce, tossing everything together and cooking for another 2 minutes.
Serve garnished with fresh basil, Parmesan cheese, and a drizzle of truffle oil.