Even before your first taste, you can tell just by the creaminess of the sauce how rich and delicious this will be. Keith advises us that this dish will taste best with freshly grated cheeses—especially Vermont Cheddar.
Bake the mixture in a deep casserole because it can easily boil over. If you decide to use a shallow pan, put it on a foil-lined baking sheet.
8 tablespoons butter, plus extra for the baking dish
1 pound penne
4 cups whole milk
6 tablespoons flour
1½ teaspoons kosher salt
¼ teaspoon cayenne pepper
2 cups (½ pound) grated sharp Cheddar cheese
2 cups (½ pound) grated Asiago cheese
2 cups (½ pound) grated fontina cheese
1 cup plain bread crumbs
½ cup (2 ounces) grated Parmesan cheese
2 tablespoons butter, melted
1 cup heavy cream
Preheat the oven to 350°F. Butter a 9 by 13-inch baking dish or 2½-quart casserole.
Bring 6 quarts of salted water to a boil. Add the pasta and cook, stirring occasionally, until al dente, 10 to 12 minutes. Drain the pasta and rinse with cold water. Drain again and place in a large bowl.
In a medium saucepan over medium heat, bring the milk to a boil. Remove from the heat.
In a medium, heavy-bottomed saucepan over medium-high heat, melt the 8 tablespoons of butter. Reduce the heat to low and whisk in the flour, cooking for 3 to 4 minutes. Be careful not to brown the mixture. Slowly add the hot milk, whisking constantly (constant whisking will ensure that there are no lumps). Add the salt and cayenne, raise the heat to medium, and simmer, stirring constantly, until the mixture has thickened, 8 to 10 minutes.
Remove from the heat and add 1 cup each of the grated Cheddar, Asiago, and fontina, whisking until the cheeses are melted. Pour the cheese sauce over the pasta, tossing to coat the pasta evenly.
Place half of the coated pasta in the buttered baking dish and distribute the remaining grated Cheddar, Asiago, and fontina over the top. Cover with the remaining pasta.
In a mixing bowl, toss together the bread crumbs, Parmesan, and melted butter. Pour the heavy cream over the pasta and evenly distribute the bread crumb mixture over the top. Bake on the middle shelf until the top is light brown and the mixture is bubbling, 30 to 35 minutes.