Start by cooking the pasta in a large pot of boiling water until it is al dente, usually around 8 to 10 minutes. You will know it is ready when it is tender but has a slight bite. Do not forget to reserve some pasta water before draining—this helps when adjusting the sauce later.
Melt the butter in a large skillet over medium heat, allowing it to get bubbly and fragrant. Add in the grated garlic and let it sauté for about 1 minute, being careful not to let it brown too much.
Pour in the heavy cream and stir with the butter, watching for it to thicken slightly. Then mix in the grated cheese until it melts and creates a smooth blend. Be mindful of the heat level; burnt bits can spoil the texture.
Drizzle in the truffle oil and stir gently to distribute it throughout the sauce. Be cautious, since too much can overpower the dish.
Add the drained pasta to the skillet and toss well with the sauce, letting the flavors meld for a moment. If the sauce feels too thick, add a splash of reserved pasta water until it reaches the desired consistency.
Taste the pasta and season it with salt or fresh pepper if needed. Serve immediately for the best flavor, as it will not hold the same creamy goodness when left to sit.