Preheat oven to 375˚F. Grease a 9x13 baking dish with cooking spray and set aside.
Toss the shredded zucchini with 1 teaspoon salt; let drain in a fine mesh strainer or colander for 10 minutes. Then, wrap up the zucchini in a kitchen towel and squeeze out the liquid as much as possible; set aside. Heat oil in a 12-inch skillet set over medium heat. Add scallions and bell peppers to the skillet and cook for 2 minutes. Stir in the garlic and cook for 15 seconds.
Stir in the shredded zucchini; cover and cook for 5 minutes, or until the zucchini has released its liquid. Uncover and continue to cook for 1 more minute; remove from heat and let the mixture cool slightly.
Meanwhile, in a mixing bowl lightly whisk the eggs to break up the yolks; then whisk in the milk, salt, and pepper until thoroughly combined.
To the eggs, stir in the zucchini mixture, the feta cheese, flour, baking powder, dill, thyme, and oregano. Transfer this mixture to the baking dish.
Bake for 20 to 22 minutes, or until the center is set and the edges begin to brown.
Remove from oven; sprinkle top with shredded cheese and continue to bake for 5 more minutes, or until cheese is melted.
Remove from oven and let stand 10 minutes.
Cut and serve.