Preheat your oven to 400°F (200°C) and lightly grease a standard 12-cup muffin tin, or line with paper liners.
Start by grating your zucchinis. Place the grated zucchini into a clean tea towel, then squeeze out as much moisture as you can.
In a large bowl, whisk together the eggs and milk until smooth. Stir in the garlic powder, onion powder, dried oregano, salt, and pepper, mixing well to distribute the seasonings.
Fold in the squeezed zucchini, mashed potatoes, Parmesan cheese, cheddar cheese (if using), and breadcrumbs. Gently mix until everything is well combined.
Spoon the mixture evenly into your prepared muffin tin, filling each cup to the top and pressing down gently to help them hold shape.
Sprinkle a pinch of extra breadcrumbs or Parmesan on top of each muffin for added crunch (optional).
Bake in the preheated oven for 22-25 minutes, or until the muffins are golden brown on top and slightly crispy at the edges.
Let the muffins cool in the tin for 5 minutes before carefully removing them. Serve warm and enjoy!
