Place the grated zucchini in a clean kitchen towel and squeeze out excess moisture. Transfer to a large mixing bowl.
Add the chopped leek and 1/2 teaspoon of salt to the zucchini. Mix well and let it sit for about 10 minutes.
After 10 minutes, stir in the flour, Parmesan cheese, eggs, black pepper, garlic powder, and remaining 1/2 teaspoon of salt. Mix until well combined.
Heat about 1/4 inch of vegetable oil in a large skillet over medium heat. Once hot, drop spoonfuls of the zucchini mixture into the skillet, flattening them slightly with the back of the spoon.
Fry the fritters for about 3-4 minutes on each side, or until golden brown and crispy. Remove from the skillet and place on paper towels to drain excess oil.
Serve warm with a dollop of sour cream or Greek yogurt on the side.