Preheat your oven to 325°F (163°C) and grease a 3-quart (9x13") baking dish. Set it aside for later use.

Bring a large pot of salted water to a boil. Add the dried elbow pasta and cook it for one minute less than the package instructions to achieve al dente texture. Drain the pasta and drizzle lightly with olive oil to prevent sticking.

While waiting for water to boil, shred all the cheese and mix together. Then, divide into three portions: approximately 3 cups for the sauce, 1 ½ cups for the inner pasta layer, and 1 ½ cups for the topping.

In a large saucepan over medium heat, melt the unsalted butter. Sprinkle in the flour and whisk to combine, creating a paste that looks like very wet sand. Cook the mixture for about 1 minute while whisking frequently to eliminate raw flour taste.

Gradually pour about 2 cups of half and half into the roux while whisking constantly to smooth out the sauce. Then add the remaining half and half plus the whole milk slowly, continuing to whisk until completely combined and smooth.

Keep the heat on medium and whisk often until the sauce reaches a very thick consistency, similar to a semi-thinned condensed soup.

Remove the sauce from the heat. Stir in salt, black pepper, paprika, and 1 ½ cups of the shredded cheeses, mixing until melted. Then stir in another 1 ½ cups of cheese until completely smooth and creamy.

In a large mixing bowl, blend the drained pasta with the cheese sauce thoroughly.

Pour half of the pasta and sauce mixture into the prepared baking dish. Evenly sprinkle 1 ½ cups of shredded cheese over it. Then add the remaining pasta mixture on top.

Sprinkle the remaining 1 ½ cups of shredded cheese evenly over the top. Bake in the preheated oven for 15 minutes until the cheese is bubbly and lightly golden brown.