Bring a large pot of salted water to a boil. Add the fettuccine and cook until al dente according to package directions. Drain, reserve 1 cup of pasta water, and set aside.,
STEP 2
In a large saucepan over medium heat, melt the butter.,
STEP 3
Slowly add the milk, then season it with salt, pepper, and garlic powder. Stir to warm the milk for 5 minutes.,
STEP 4
Transfer the reserved cooked pasta on top of the butter and milk mixture. Add the reserved pasta water and stir until the sauce clings to the pasta.,
STEP 5
Turn off the heat, add the grated cheeses and stir until the sauce has thickened and well combined with the pasta, about 5 more minutes. Serve immediately.