In one bowl, beat together eggs, salt, and pepper to taste. Set aside. In another bowl, combine breadcrumbs, parmesan, Italian seasoning, garlic powder, and additional salt and pepper. Set aside. Add all-purpose flour to third bowl. Set aside.
Pour enough oil into pan to create ½-inch-deep layer and place pan over medium heat.
Dredge zucchini discs through flour. Tap disc against side of bowl to shake off excess flour, then fully dip floured zucchini in egg mixture, coating both sides. Let excess egg drip back into bowl, then dip zucchini in breadcrumb mixture.
Coat both sides of zucchini disc thoroughly, then set aside and repeat with remaining discs.
When oil is hot, add discs to pan in batches, being careful not to overcrowd pan. Lay discs in a single layer so they don't touch or overlap.
Cook zucchini discs 2 to 3 minutes, then flip and cook another 2 to 3 minutes. Remove fried zucchini discs and place on plate lined with paper towels or on cooling rack set over paper towels, to drain any excess oil. Repeat until all zucchini discs are fried. If desired, season fried zucchini discs immediately with additional salt. Serve with parmesan dipping sauce and/or marinara.