Add the butter to a deep-sided 10 to 12-inch skillet or 5 to 6-quart saucepan over medium heat. Allow the butter to melt.
Once the butter is melted, add the minced garlic. Stirring often to ensure the garlic does not burn. Cook for 1 to 1½ minutes.
Add the cream cheese and continue cooking for 3 to 4 minutes until the cream cheese has melted. Be sure to stir constantly to keep the cream cheese from scorching.
Whisk in the reserved pasta water or broth, onion powder, oregano, kosher salt, and pepper. Continue whisking for another 3 to 5 minutes until completely incorporated and smooth.
Remove the pan from the heat and whisk in the grated parmesan cheese. Continue whisking until the cheese is melted.
Add in the cooked pasta and stir to combine. Garnish with the fresh chopped parsley. Serve immediately.
Notes
To speed up the cooking process and get a smooth sauce faster, set the block of cream cheese out about 30 minutes before using it.
Be sure to stir constantly to keep the cream cheese from scorching.
To help make your sauce extra creamy, allow your parmesan cheese to come to room temperature before adding it to the sauce.