Crush cheese puffs into a fine powder and set aside.
In a saucepan over medium heat, add the butter. Once the butter is melted, add milk, cheddar, mozzarella, and cream cheese. Whisk until all the cheese has melted and sauce is smooth.
Pour cheese sauce over cooked pasta, stirring to ensure thorough coverage of the noodles.
Cover and refrigerate the cheese-coated pasta for at least 2 hours, allowing for it to cool completely and for the cheese sauce to bind the pasta together. This recipe also works well with leftover mac ‘n’ cheese.
Using your hands, take the chilled mac ‘n’ cheese and form it into 1-inch (2 ½ cm) balls.
Dredge the balls in flour, followed by egg before finally coating them in the powdered cheese puffs.
Heat the oil to 350˚F (180˚C) and fry the mac ‘n’ cheese balls until the outside is crispy, about 2 minutes. Once done frying, transfer to a wire rack to drain. Lightly sprinkle with salt before serving.