Add pasta, milk, and water to the pot and stir gently so the pasta doesn’t stick.
Cook over medium heat and bring to a gentle simmer, stirring often so the milk doesn’t scorch
Simmer for about 10–12 minutes (depending on the pasta type), stirring every minute or so, until pasta is tender and the liquid reduces and thickens.
Turn off the heat and stir in butter once the pasta is cooked and there’s still a little creamy liquid in the pot.
Add shredded cheese slowly, a handful at a time, stirring until melted before adding more.
Add salt, pepper, and garlic powder, then taste and adjust. Serve immediately while hot and melty.