Preheat oven to 325 degrees.
Fill a large pot with salted water and bring to a boil. Cook your pasta according to package directions until just 1 minute shy of al dente (mine was 5 minutes). Drain well, then return to the pot and toss with 1 tablespoon olive oil so it doesn't stick together in a clump while making the sauce.
While the pasta is cooking, grate the cheeses. You are going to add the cheese in 4 stages, so it might be helpful to divide them into fourths now.
In a large saucepan, melt the butter over medium heat. Once the butter is melted, add the flour and whisk well, cooking for one minute until completely combined and the roux begins to look a bit like wet sand.
Slowly add the cream and 1 cup of the milk, whisking continuously, until smooth and completely combined. Add the remaining 2 cups of milk, whisking and cooking over medium heat until the sauce thickens a bit, about 3 to 4 minutes.
Stir in the salt, pepper, paprika and garlic powder, then add ¼ of each of the grated cheeses except the medium cheddar, which you will save just for topping the mac & cheese. Once the cheese has melted, add another ¼ of the grated cheeses and stir until it also melts and incorporated into the sauce.
Pour the sauce over the cooked pasta and stir to combine. Pour half of the pasta & sauce into a large 9x13" baking dish, then sprinkle another ¼ of the grated cheeses over that layer, then repeat with the remaining pasta and sauce, the remaining cheese and finally sprinkle the grated medium cheddar over the top.
Transfer the macaroni & cheese to the oven and bake, uncovered, for 15 minutes, until the cheese is completely melted and bubbly. Serve immediately.