Shred all the cheese (except for the Velveeta) and toss them together in a large bowl to combine them.
Cook the pasta shells in salted water for 2 minutes under the recommended time on the back of the package. Strain them and leave them in the colander. Place the same pot that boiled the pasta in on same burner that was just used with the heat OFF.
Add the Velveeta, butter and shells. Season the pasta with salt, pepper and garlic powder and stir everything together until the butter and most (if not all) the Velveeta is melted.
Pour in the heavy cream. Add almost all of the shredded cheeses. (Keep about 1.5 cups to add to the top later. Stir everything together). Stir until evenly combined.
Add the mixture to a greased 9 x 13" baking dish and sprinkle the rest of the cheese on top.
Place it into the center rack of the oven, uncovered, for about 30 minutes or until the cheese is melted and the sides are bubbly.
Let it sit for about 5-10 minutes before serving, garnish with parsley (optional) and enjoy!
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