01 - Cook the elbow macaroni in salted boiling water until al dente according to package directions. Drain thoroughly and set aside.
02 - Melt butter in a saucepan over medium heat. Stir in flour and cook for 1 minute, stirring constantly. Gradually whisk in milk until smooth and continue cooking for 2-3 minutes until thickened, stirring frequently.
03 - Remove saucepan from heat. Stir in shredded cheddar cheese, salt, black pepper, and paprika until cheese is completely melted and sauce is smooth. Add cooked macaroni and mix until evenly coated. Spread mixture onto a baking tray and refrigerate for at least 1 hour until very firm.
04 - Scoop chilled macaroni mixture into 1.5-inch balls, pressing firmly to compact. Place balls on a parchment-lined baking sheet and freeze for 30 minutes until firm.
05 - Arrange three shallow bowls: place flour in the first bowl, beat eggs with milk in the second bowl, and combine panko breadcrumbs with Parmesan cheese in the third bowl.
06 - Dredge each chilled ball in flour, shaking off excess. Dip into egg mixture, then coat thoroughly with panko-Parmesan mixture, pressing gently to ensure breading adheres evenly.
07 - Heat 2 inches of vegetable oil in a deep pot to 350°F. Fry balls in batches, turning occasionally, until golden brown and crispy, approximately 2-3 minutes per batch. Remove with a slotted spoon and drain on paper towels.
08 - Arrange fried macaroni and cheese balls on a serving platter and serve immediately with warm marinara sauce for dipping.