When food is fried and has tons of cheese, you know it's going to be good.
Cut the ends off the zucchini, and cut each in half crosswise. With an apple corer, remove the center of each zucchini piece, and stuff them with 1 mozzarella log. Cut the stuffed zucchini crosswise again into 1/2-inch-thick rounds.
Place flour in a shallow dish, eggs in a second shallow dish, and breadcrumbs in a third. Dredge each stuffed zucchini round in flour, dip them in the egg, (make sure to shake off excess) and then dip them in the breadcrumbs, pressing to adhere.
Heat oil in small saucepan over medium-high. Fry the coated zucchini rounds 3 at a time, occasionally turning them with a fork, until golden brown, about 3 minutes. Transfer the fried zucchini rounds to a plate lined with paper towels to drain, then sprinkle with salt. Serve with marinara sauce.