Cook the macaroni according to package directions and set aside.

Melt the butter in a skillet over medium heat. Stir in the flour and cook, stirring constantly, until it forms a smooth paste. Gradually stir in the heavy cream and whole milk.

Add the cream cheese, Cheddar cheese, and mustard powder. Continue stirring until the cheese melts and the sauce thickens. Stir in the macaroni until fully coated.

Spread the mac and cheese into a baking dish and refrigerate for at least 3 hours or overnight until firm.

Scoop the chilled mac and cheese into balls using a cookie scoop and place them on a baking sheet.

In one bowl, combine the flour, salt, pepper, garlic powder, and paprika. In a second bowl, beat the eggs. In a third bowl, add the panko breadcrumbs. Dredge each mac and cheese ball in the flour mixture, dip into the eggs, then coat in panko. Place back on the baking sheet and refrigerate for 15 minutes or up to overnight.

Heat about an inch of oil in a medium skillet over medium heat. Fry several mac and cheese balls at a time, turning as needed, until golden brown.

Transfer the fried mac and cheese bites to a paper towel-lined baking sheet using a slotted spoon. Sprinkle with flaky sea salt if desired and serve warm.