**Prepare the Cheese Cubes:** Cut the mozzarella into bite-sized cubes and set aside.
**Crush the Doritos:** Place Doritos in a ziplock bag and crush into fine crumbs using a rolling pin or food processor. Transfer the crumbs to a bowl.
**Prepare Breading Stations:** In three separate bowls, place flour, beaten eggs, and crushed Doritos (breadcrumbs, if using).
**Bread the Cheese:** Coat each cheese cube in flour, then dip it in the egg, and finally roll it in the Doritos crumbs until fully coated. For extra crunch, repeat the egg and crumb coating.
**Heat the Oil:** Heat vegetable oil in a saucepan or deep fryer to 350°F (175°C).
**Fry the Cheese Cubes:** Fry a few cubes at a time, about 1–2 minutes, until golden brown and crispy. Remove with a slotted spoon and drain on paper towels.
**Serve:** Serve hot with your favorite dipping sauces like marinara, ranch, or spicy mayo.