Start by bringing a big pot of salted water to a boil. Cook the fettuccine until it’s just tender (al dente!), following the package directions. Before draining, scoop out about a cup of the pasta water and set it aside — you might need it to loosen up the sauce later.
Meanwhile, in a large skillet over medium heat, melt the butter. Let it cook, giving the pan a gentle swirl now and then, until it starts to foam and turns a rich golden brown color. You’ll know it’s ready when it smells nutty and toasty — this usually takes about 4 to 5 minutes, so keep a close eye on it! Once your butter is perfectly browned, stir in the minced garlic and let it sizzle for about 30 seconds, just until fragrant.
Remove the pan from the heat right away so the garlic doesn’t burn. Turn the heat down to medium-low and place the skillet back on the burner.
Slowly pour in the heavy cream, whisking as you go to blend it into the butter. Stir in the cheeses and keep mixing until the sauce is smooth and melty. If the sauce is thicker than you'd like, gradually stir in a bit of the reserved pasta water — a splash at a time — until you reach your desired saucy consistency.
Toss the cooked fettuccine right into the skillet and coat it in all that luscious sauce. Season to taste with salt and pepper AND don't forget to sprinkle generously with McCormick's Brown Butter Finishing Salt!
Serve immediately, and if you're feeling fancy, top it with extra Parmesan and a sprinkle of fresh parsley or basil for a pop of color.