Add water, cream, garlic powder, onion powder, paprika, and mustard powder to a Dutch oven over medium-high heat and whisk until smooth.
Bring to a boil, add pasta, and stir well.
Reduce heat to medium and simmer uncovered for 8-10 minutes, stirring every minute, until pasta is al dente and most liquid is absorbed.
Turn off heat and stir in Velveeta cubes until mostly melted.
Add sharp cheddar and stir until smooth and creamy.
Remove from heat, season with salt and pepper, and serve immediately.