Boil pasta in salted water until al dente, about 8 minutes. Reserve 1/4 cup pasta water and drain.
Heat olive oil in a wide skillet over high heat. Add mushrooms, sautéing until golden brown, about 5 minutes. Listen for sizzling; if silent, increase heat.
Add garlic to mushrooms, cooking until fragrant, about 30 seconds. The aroma should be pungent but not burnt.
Lower heat to medium. Stir in heavy cream, bringing to a gentle simmer. Avoid boiling to prevent curdling.
Stir in Parmesan cheese until melted and smooth. The sauce should thicken slightly, clinging to the back of a spoon.
Add cooked pasta to the skillet, tossing to coat in sauce. If too thick, gradually add reserved pasta water to loosen.
Season with salt and black pepper to taste. Taste and adjust seasoning as needed.
Serve immediately, garnished with additional Parmesan and black pepper if desired.
Notes
Ensure cream is at room temperature to prevent curdling.