Add the macaroni to a large pot.
Pour in the half-and-half, then add enough water to just cover the pasta.
Bring to a gentle boil, stirring occasionally to prevent sticking.
Continue cooking until the pasta is tender and most of the liquid has been absorbed. Do not drain.
Reduce the heat to low.
Stir in the butter until melted.
Add the garlic powder, onion powder, salt, black pepper, and smoked paprika if using.
Gradually stir in the shredded cheddar until completely melted and creamy.
If the sauce becomes too thick, stir in a splash of half-and-half or milk until it reaches your desired consistency.
Serve immediately.