Preheat oven to 325°F and grease a 3-quart (9×13-inch) baking dish. Set aside.

Bring a large pot of salted water to a boil. Cook pasta 1 minute less than package instructions for al dente. Drain and drizzle lightly with olive oil.

Shred and combine cheeses, then divide into three portions:

3 cups for the sauce

1½ cups for the middle layer

1½ cups for the topping

Melt butter in a large saucepan over medium heat. Whisk in flour and cook for 1 minute.

Slowly whisk in about 2 cups of the half and half until smooth, then add remaining half and half and milk, whisking constantly.

Cook, whisking frequently, until sauce thickens to a very thick, creamy consistency.

Remove from heat and stir in salt, pepper, paprika, and 3 cups of cheese in two additions, stirring until fully melted and smooth.

Combine pasta with cheese sauce. Pour half into the baking dish, sprinkle with 1½ cups cheese, then add remaining pasta.

Top with the final 1½ cups of cheese and bake for 15 minutes, until bubbly and lightly golden.