Preheat your oven to 375°F (190°C) and grease a medium-sized baking dish with olive oil.

In a large bowl, whisk together sour cream, mayonnaise, minced garlic, salt, black pepper, and chopped parsley until smooth.

Slice the zucchini thinly and add it to the creamy mixture, tossing gently until coated.

Transfer the zucchini mixture into the baking dish, spreading it out evenly.

Sprinkle mozzarella and Parmesan cheese over the zucchini mixture evenly.

Bake for 25 to 30 minutes until the zucchini is tender and the cheese is golden brown.

Let cool for about 5 minutes before serving.