Ingredients
Equipment
Method
- Arrange one rack in the top position and a second rack in the middle of the oven. Heat the oven to 375°F. Bring a large pot of heavily salted water to a boil over medium-high heat.
- Add the dried spaghetti to the boiling water and cook for 1 minute less than al dente. Meanwhile, prepare the sauce.
- Melt the butter in a medium pot over medium heat. Whisk in the flour and cook until golden brown and toasted, about 2 minutes.
- Slowly whisk in the milk and heavy cream. Bring to a boil, whisking occasionally. Reduce heat to a simmer and cook until the sauce slightly thickens, about 5 minutes. Remove from heat.
- Whisk in the shredded mozzarella, 3 ounces of the Parmesan cheese, garlic powder, and 1 teaspoon kosher salt until smooth.
- Drain the spaghetti and add it to the sauce. Toss to combine. Taste and season with more salt if needed. Transfer to a broiler-safe baking dish and spread into an even layer. Sprinkle with the remaining mozzarella and Parmesan cheese.
- Bake on the middle rack until the edges bubble and the cheese melts, about 20 minutes. For extra browning, move the dish to the top rack and broil until the cheese is browned, 3 to 4 minutes. Let cool for 5 minutes. Garnish with parsley if using before cutting and serving.
Notes
Make ahead: Cover the unbaked, assembled spaghetti with aluminum foil and refrigerate for up to 2 days or freeze for up to 3 months. Thaw in the refrigerator overnight. Bake, still covered, at 350°F until heated through and bubbling around the edges, about 20 minutes. Uncover and bake until the cheese on top is golden brown, 15 to 20 minutes more.
Storage: Refrigerate leftovers in an airtight container for up to 4 days. The baked spaghetti will lose some of its creaminess upon refrigeration. Add a splash of milk during reheating to loosen the sauce.