Grate the zucchini using the large holes on a grater. Place it in a bowl and sprinkle with 1/2 teaspoon kosher salt. Allow it to stand at room temperature for 10 minutes while you prep the other ingredients. Then squeeze out all the moisture with your hands in batches, and use a paper towel or clean dish towel to squeeze out all extra moisture.
In a small bowl, whisk the egg, then add the grated garlic. In a large bowl, whisk the all-purpose flour, Parmesan cheese, dried dill, onion powder, baking powder, and remaining 1/2 teaspoon plus 1 large pinch kosher salt. Season with a few grinds of black pepper. Add the zucchini and egg mixture and gently mix with a spatula until a sticky dough comes together.
Heat a large non-stick skillet over medium heat. Add enough olive oil to coat the bottom of the skillet by about 1/8-inch (about 2 tablespoons to start). Add the fritters by dropping them from 1/4 cup measure, then spreading them slightly thinner with the back of the measuring cup. Fry the fritters in batches that fit the skillet, about 2 to 3 minutes per side until golden. Add a drizzle more olive oil when necessary. Make sure the heat is not too high or the fritters will become browned on the outside but stay gooey in the middle.
Remove each fritter and place it on a plate lined with a paper towel to drain excess oil. Eat immediately; the fritters taste best the day they are made. Leftovers store refrigerated up to 2 days; reheat in a skillet.