Cook the Macaroni: Bring a large pot of salted water to a boil. Add the elbow macaroni and cook until al dente, about 7-9 minutes. Drain and set aside.
Prepare the Cheese Sauce: In a medium saucepan, melt butter over medium heat. Add garlic powder, onion powder, smoked paprika, salt, and pepper, and cook for 1-2 minutes. Gradually whisk in milk and cream, bringing to a simmer. Slowly add cheddar and Monterey Jack cheeses, stirring until the sauce is smooth. Temper the eggs by mixing a small amount of the hot sauce into the eggs, then stir the egg mixture into the sauce. Continue cooking until thickened.
Combine Pasta and Sauce: Add the cooked macaroni to the cheese sauce and stir until the pasta is evenly coated.
Prepare for Baking: Preheat your oven to 350°F (175°C). Transfer the mac and cheese mixture into a greased 9x13-inch baking dish. Sprinkle the top with Parmesan cheese and breadcrumbs, if using.
Bake: Bake for 25-30 minutes, or until the top is golden and crispy. For an extra crispy topping, broil for 1-2 minutes at the end.
Serve: Let rest for 5 minutes before serving. Enjoy!