- 1 (16 ounce) package cavatappi (corkscrew macaroni)
- 6 tablespoons butter
- 1/2 cup flour
- 5 1/2 cups milk, divided
- 2 1/2 cups shredded smoked Gouda cheese
- 2 cups shredded sharp Cheddar cheese
- 1 1/2 cups shredded Swiss cheese
- 1 1/2 cups grated Parmesan cheese, divided
- 1/2 cup dry bread crumbs
- 1 tablespoon truffle oil
- Preheat oven to 350 degrees F (175 degrees C). Butter a 9×13-inch baking dish.
- Bring a large pot of lightly salted water to a boil. Cook cavatappi in boiling water, stirring occasionally, until cooked through but firm to the bite, about 8 minutes. Drain.
- Melt butter in a large pot over medium-low heat. Whisk flour into butter until mixture has a thick, paste-like consistency, about 30 seconds. Slowly whisk 2 cups milk into butter-flour mixture until smooth. Stir in remaining milk, increase heat to medium high, and cook, whisking constantly, until mixture is thick and almost boiling, 5 to 10 minutes.
- Stir Gouda cheese, Cheddar cheese, Swiss cheese, and 1 cup Parmesan cheese into milk mixture until cheese melts and cheese sauce is smooth. Fold cavatappi into cheese sauce; pour mixture into prepared baking dish.
- Stir remaining Parmesan cheese and bread crumbs together in a small bowl. Sprinkle bread crumbs mixture over cavatappi mixture and drizzle truffle oil over the top.
- Bake in the preheated oven until golden and bubbling, about 30 minutes. Cool for 10 minutes before serving.