Working with one piece of mozzarella at a time, dredge in flour, shaking off excess. Dip in egg mixture, then coat in breadcrumbs, pressing to adhere. (Tip: Keep one hand clean to transfer from one dish to the next to avoid clumping or keep a bowl of water handy to dip into a bowl between dipping) Repeat steps for a second coating. Transfer to a wire rack set inside a rimmed baking sheet. Repeat with remaining mozzarella. Transfer rack with mozzarella to freezer and freeze at least 1 hour and up to 3 days.