Preheat the oven to 200 C.
Slice the zucchini into ½ cm rounds.
Add the flour to a plate and set aside. Whisk the egg with 2 tbsp water in a flat bowl and set aside.
Mix together the panko, grated parmesan, garlic powder, pepper and salt on a plate (taste the mixture before adding the salt as parmesan is already salty).
The order: lightly dredge the zucchini rounds in flour, roll them a few times in the egg, and then transfer to the panko mixture. Coat the zucchini on both sides pressing firmly with your fingers to make sure the crumbs stick. Transfer to a baking tray. Repeat in batches for the rest of the zucchini.
Brush/spray the tops with olive oil. Bake for 25-30 mins until golden. No flipping necessary. Serve hot as a side with pasta or as an appetizer with your favourite dip to dunk into.