Preheat the oven to 400°F (200°C). Lightly grease a 12-cup muffin tin with olive oil.
Grate the zucchini and potatoes, then squeeze out excess moisture using a clean kitchen towel.
In a large bowl, mix the grated zucchini and potatoes with Parmesan cheese, flour, eggs, garlic, onion powder, salt, pepper, and parsley until well combined.
Spoon the mixture evenly into the prepared muffin tin, pressing down gently to pack.
Bake for 25-30 minutes, or until the tops are golden brown and crispy.⏱ 30 min
Let cool slightly before removing from the muffin tin. Serve warm or at room temperature.