Slice zucchini thinly and sprinkle with salt. Let rest 10 minutes, then pat dry.
Heat olive oil over medium-high heat. Sauté mushrooms until golden (6–8 minutes).
Stir in spinach and garlic until wilted. Remove from heat.
In a bowl, combine cottage cheese, Greek yogurt, half of the mozzarella, and Parmesan.
In a baking dish, spread cheese mix, add zucchini slices, then mushroom-spinach mix. Repeat.
Finish with mozzarella. Cover with foil and bake 25 minutes at 375°F, then uncover for 15 minutes more.
Cool 10 minutes before slicing and serving.
