Cook pasta to al dente according to the pkg directions. Drain and set aside.
Shred all your cheeses and divide them in half.
Heat a pot on medium heat and melt the butter. Once melted add in the heavy cream, whisk until smooth. Bring to a low simmer (depending on the size of your pot it may take 5-6 minutes. Keep whisking it every so often so it doesn't burn.)
Reduce heat to low and add in half of your shredded cheeses and all of your Velvetta, garlic powder, onion powder, paprika, ground mustard and let simmer on low until everything in melted and creamy. (Don't turn the heat up or it may become grainy)
Add in your cooked pasta.
Transfer 1/2 of the pasta cheese sauce to a 9x13 baking dish add 1/2 of the remaining shredded cheese on top. Followed by the remaining noodles on top and the remaining shredded cheese on top for the final layer.
Place the dish on a baking sheet to catch anything that boils over the top. Bake uncovered for 30 minutes or until hot and bubbly.
Let your mac and cheese sit for 15 minutes to thicken up. Serve!
Notes
You can certainly swap out any of the cheeses for what you prefer.
The sauce will thicken up and soak into the pasta as it cools.
Store leftovers in an airtight container for 3-4 days.