Prepare the zucchini : Wash and trim the ends off the zucchinis. Using the coarse side of a box grater, grate them into a large bowl. Sprinkle with 1 teaspoon of salt and stir gently to combine. Let the salted zucchini rest for 10 minutes—this step helps draw out excess moisture, which is key for crispy fritters.
Remove moisture : After 10 minutes, transfer the zucchini to a clean kitchen towel or cheesecloth. Twist and squeeze tightly over the sink to remove as much water as possible. The drier the zucchini, the better the texture of your fritters.
Mix the batter : In a large mixing bowl, combine the drained zucchini, chopped green onions, eggs, flour, Parmesan cheese, mozzarella (if using), garlic powder, and freshly ground black pepper. Mix until all ingredients are evenly distributed. The mixture should be thick but not dry—adjust with a small splash of milk or extra flour if needed.
Preheat the pan : Place a large non-stick or cast iron skillet over medium heat. Add 1 to 2 tablespoons of olive oil and let it heat until shimmering but not smoking.
Form and cook the fritters : Scoop about 2 tablespoons of the batter for each fritter and drop it into the hot pan. Use a spatula to flatten each mound slightly into a round disc (about ½ inch thick). Don’t overcrowd the pan—work in batches if necessary.
Fry to golden perfection : Cook each fritter for 2 to 3 minutes per side, or until the edges are golden brown and the center feels firm. Flip gently using a wide spatula. If they brown too quickly, reduce the heat slightly.
Drain and serve : Transfer the cooked fritters to a paper towel-lined plate to drain excess oil. Repeat with the remaining batter, adding more oil as needed.
Garnish and enjoy : Serve warm, topped with a dollop of sour cream or Greek yogurt, a squeeze of lemon, or a sprinkle of fresh herbs. They’re best enjoyed right away, but leftovers reheat beautifully.