Keep 1 medium green zucchini at 68°F to 72°F for 20 minutes so the flesh slices cleanly. Cut it crosswise into exactly 24 coins, each 1/4 inch thick. Use steady downward strokes and rotate the zucchini after several cuts. Lay the coins between clean towels and press with flat palms for 10 minutes. Replace any towel that becomes soaked. The faces should look matte and pale green while the dark skins stay firm. You'll feel slight tackiness but no slick water. If beads remain after minute 10, blot for 2 more minutes. Rush this window and trapped moisture steams the crumbs loose during cooking. Dry surfaces grip flour and egg, so the crust sets instead of sliding.

Keep the flour, egg and crumb mixture at 68°F to 72°F while you work for 6 to 8 minutes. Whisk the egg until no clear streaks remain. Stir plain panko breadcrumbs, Parmigiano Reggiano, garlic powder, dried Italian seasoning, Diamond Crystal kosher salt and black pepper together. Dredge each coin in unbleached all-purpose flour, dip it in egg and press both faces firmly into the crumbs. The coating should look rough and sandy with small patches of dark green rim still visible. Shake each coin once so loose crumbs fall away. If bare wet spots remain, press on another pinch of crumbs before moving on. Miss those gaps and steam breaks through the crust. Layered coatings create separate barriers that turn crisp instead of pasty.

Preheat the air fryer to 390°F for 3 minutes. Divide all 24 coated coins between two basket zones, placing 12 in each single layer. Leave about 1/4 inch between pieces and mist both faces with 2 teaspoons extra-virgin olive oil. Air fry for 5 minutes without opening the baskets, so the first crust can firm before turning. The crumbs should look dry and pale gold by minute 5. You'll smell toasted cheese before the edges deepen. A few tiny crumbs may crackle against the basket, but the centers should stay flat. (I packed my first batch too tightly, the centers stayed soft and the crust peeled.) Overlap traps steam and leaves damp patches. Fast circulating heat dries the coating before the zucchini collapses.

At minute 5, turn every coin with a gentle edge grip and shift the outer pieces toward each basket's center. Mist only dry floury spots with a light extra spray from the measured oil. Continue at 390°F for 4 to 6 minutes. Check the smallest coins at minute 4 because they darken faster than wide center slices. The second face should become deep gold with scattered amber freckles. The edges feel rigid and you'll hear a faint crisp scrape when a coin moves. The zucchini inside should yield slightly without bending limp. Go past minute 6 and the cheese tastes bitter before the center improves. Turning exposes wet crumbs to direct airflow, which completes browning on both faces.

Transfer the 24 chips from the baskets and let them rest at 68°F to 72°F for exactly 2 minutes. Divide them among four plates, placing 6 chips on each plate with loose overlap. Scatter 2 tablespoons chopped flat-leaf parsley and the reserved 2 tablespoons Parmigiano Reggiano across all portions. Don't cover the plates while the chips release their first burst of steam. The crust should crackle lightly while the centers stay tender and pale. Look for dark green rims, uneven golden faces and a few loose crumbs between chips. Stacking them immediately traps steam and softens the lower pieces. Serve after minute 2 while the cheese still smells nutty. A brief uncovered rest lets escaping moisture preserve the crust.