Place shredded zucchini in a bowl and toss with 1/2 teaspoon salt; let stand for 15 minutes. Transfer into a clean kitchen towel and wring out excess liquid into the sink.
Preheat the oven to 350 degrees F (175 degrees C). Grease a 9-inch pie plate.
Combine zucchini, eggs, baking mix, onion, melted butter, Cheddar cheese, Parmesan cheese, rosemary, parsley, and pepper in a large bowl; mix well.
Spread mixture into the prepared pie plate or baking pan.
Bake in the preheated oven until golden brown and a knife inserted in the center comes out clean, about 45 minutes.