Freeze your assembled mac and cheese balls for at least 4 hours or overnight before frying—this prevents the filling from leaking out and ensures a crispy exterior while keeping the interior perfectly molten.

After coating in breadcrumbs, dip each ball back into the egg wash and breadcrumbs a second time, then refrigerate for 15 minutes before frying to achieve an exceptionally thick, crunchy crust.

Maintain your oil at 350°F using a kitchen thermometer—too cool and they'll be greasy, too hot and the outside burns before the inside heats through, resulting in a cold center.

Always work with thoroughly chilled leftover mac and cheese directly from the refrigerator, as warm or room-temperature paste won't hold together properly when shaping and will fall apart during frying.

Press the mozzarella ball deep into the center of each mac and cheese ball and fully encase it, ensuring it's completely surrounded so the cheese doesn't rupture through the coating while frying.