Bring a large pot of salted water to a boil. Add the elbow macaroni and cook 1 minute less than the package instructions (about 7-8 minutes). Drain the pasta and toss with 2 tablespoons butter to prevent sticking. Set aside.
Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking dish.
Shred all cheeses and mix them in a bowl, reserving 1 cup of cheddar for the topping.
In a large bowl, whisk together milk, heavy cream, eggs, sour cream, salt, pepper, smoked paprika, and garlic powder until smooth.
Layer half of the cooked macaroni in the baking dish. Sprinkle half of the shredded cheese mixture over the pasta. Repeat with another layer of pasta and cheese.
Pour the creamy milk mixture evenly over the macaroni and cheese, ensuring everything is well coated.
In a small bowl, mix Ritz cracker crumbs (or panko) with melted butter. Sprinkle the reserved 1 cup of cheddar cheese over the mac and cheese, followed by the buttery crumb topping.
Cover with foil and bake for 30 minutes. Remove the foil and bake for another 10-15 minutes until the top is golden brown and bubbling.
Allow the mac and cheese to sit for 5-10 minutes before serving. This helps it set and become extra creamy!