01 - Cook macaroni in salted boiling water according to package directions. Drain thoroughly and set aside.
02 - Melt butter in a saucepan over medium heat. Whisk in flour and cook for 1 minute, stirring constantly to create a smooth paste.
03 - Gradually whisk in milk and cook until slightly thickened, about 2-3 minutes. Reduce heat, add cheddar, mozzarella, salt, pepper, and paprika. Stir until completely smooth and cheeses are melted.
04 - Add drained macaroni to the cheese sauce and mix thoroughly to coat every piece evenly.
05 - Transfer mixture to a parchment-lined baking sheet. Spread evenly, cover, and refrigerate until firm, at least 2 hours (or 30 minutes in the freezer for faster results).
06 - Scoop heaping tablespoons of the chilled macaroni mixture and roll into 1.5-inch balls. Place on a clean tray.
07 - In three separate bowls, arrange: flour, eggs whisked with 2 tbsp milk, and breadcrumbs.
08 - Dredge each ball in flour, shake off excess, dip in egg mixture, then coat thoroughly with breadcrumbs. Return to tray.
09 - Heat 2 inches of vegetable oil in a deep pot to 350°F.
10 - Fry balls in batches, turning occasionally, until golden brown and crispy, about 2-3 minutes per batch. Drain on paper towels.
11 - Serve immediately with warm marinara sauce. Garnish with chopped fresh parsley if desired.