Bring a large pot of salted water to a rolling boil and cook the elbow macaroni until just al dente, about 8 minutes. Drain and set aside.
Melt the butter in a saucepan over medium heat until it starts to foam and smells nutty, about 1 minute. Add garlic powder and smoked paprika, stirring until fragrant, about 30 seconds.
Pour in the milk and heavy cream, warming gently until steaming and just about to simmer, about 3-4 minutes. Whisk in small handfuls of grated cheese, waiting for each to melt before adding more, until the sauce is smooth and cheesy.
Season the sauce with black pepper and taste; adjust salt if needed. The sauce should be creamy, cheesy, with a slight smoky aroma.
Add the cooked pasta to the sauce and stir well to coat evenly. If the sauce seems too thick, splash in a little more milk and stir until it reaches your preferred consistency.
Transfer the cheesy pasta mixture into an oven-safe dish and spread out evenly. Sprinkle generously with breadcrumbs and extra cheese if desired for a golden, crispy topping.
Bake in a preheated oven at 180°C (356°F) for 15–20 minutes. Look for bubbling edges and a golden, crispy crust on top. If not quite there, bake a few more minutes until perfect.
Remove from the oven and let sit for 5 minutes; this helps the sauce thicken slightly and makes serving easier. The top should be crispy, and the inside creamy and cheesy.
Serve hot, scooping generous portions that reveal the gooey cheese and crispy topping. Enjoy the smoky, cheesy goodness with a crunchy crown on top.