Boil Cavatappi Pasta: Bring a large pot of salted water to a rolling boil. Cook cavatappi 1 to 2 minutes shy of package directions until firm al dente (about 8 minutes). Drain and set aside—do not rinse!

Toast Golden Panko Topping: In a small skillet over medium heat, melt 1.5 tbsp butter. Add panko breadcrumbs and garlic powder. Stir constantly for 3 to 4 minutes until deeply golden and toasted. Transfer to a bowl and toss with minced parsley.

Make the Roux: In the same large pasta pot over medium heat, melt 4 tbsp butter. Whisk in flour and cook for 1 minute until fragrant and lightly bubbling, without browning.

Whisk Liquid & Thicken: Slowly stream in warmed milk and heavy cream in a steady drizzle while whisking continuously to prevent lumps. Whisk in Dijon mustard, garlic powder, onion powder, white pepper, nutmeg, and salt. Simmer gently for 3 to 4 minutes until thickened enough to coat the back of a wooden spoon.

Melt the Cheeses: Turn heat to the lowest setting (or remove pot from heat). Whisk in softened cream cheese until smooth. Add freshly grated sharp white cheddar and gruyère one handful at a time, whisking gently between additions until silky smooth and fully melted.

Combine & Serve: Pour drained cavatappi into the warm cheese sauce. Fold gently with a spatula until every spiral is generously coated in velvety cheese. Spoon into bowls, shower with crunchy golden garlic butter panko crumbs, and enjoy steaming hot!