In a large pot, add 5 cups of water a little salt and bring to a boil. Pour in pasta. Let it cook slowly until most of the water cooks away. Be sure to cook pasta one minute shy of al dente (still a bit firm) according to the package instructions. This will allow the noodles to not overcook in the oven.
Remove from heat but DO NOT DRAIN WATER. There should be a little water left in the pasta. If there is a ton of water left, you can drain off a little, but be sure to leave at least 1 cup of pasta water. This will help with the creamy texture.
To the noodles and pasta water, add butter and the cubed Velveeta Cheese (or cheese of choice) and mix until combined with a spoon. Add salt and pepper to taste
Coat a 9×13 casserole dish with cooking spray and transfer the creamy mac and cheese to the dish. Evenly spread out.
For an even cheesier flavor, add 1 1/2 cup shredded cheddar cheese to the top of the noodles.
Crumble the 1 1/2 sleeves of Ritz crackers in a food processor. Transfer the crumbled crackers evenly over the top of the mac and cheese.
Bake in a 350 degree oven covered with aluminum foil for about 15 mins. Take off foil and let topping brown for approximately 5 mins.