In a large mixing bowl, combine the ricotta cheese, half of the mozzarella, half of the Parmesan, minced garlic, egg, dried oregano, red pepper flakes, salt, and black pepper. Mix until well combined.
In a lightly greased baking dish, arrange a layer of zucchini slices at the bottom. Spread half of the cheese mixture over the zucchini. Repeat this layering with the remaining zucchini slices and cheese mixture.
Sprinkle the remaining mozzarella and Parmesan cheese evenly over the top layer of zucchini.
In a small bowl, combine the breadcrumbs with a drizzle of olive oil and a pinch of salt. Mix to combine, then sprinkle the breadcrumb mixture over the top of the bake.
Cover the baking dish with aluminum foil and bake for 25 minutes.
After 25 minutes, remove the foil and bake for an additional 15-20 minutes, or until the top is golden and bubbly.
Let the bake cool slightly before slicing. Garnish with fresh parsley before serving.
Notes
Serve with a fresh green salad for a colorful contrast!