Preheat your oven to 425°F.

Prepare a baking dish by buttering it and placing it aside.

Slice the zucchini into ¼-inch rounds and sprinkle salt over each piece. Allow the slices to sit for about 15 minutes to extract moisture.

Afterward, use a paper towel to gently pat each slice to remove excess salt.

Layer the zucchini slices in the prepared baking dish and set them aside.

In a bowl, combine heavy cream, sour cream, Italian seasoning, onion powder, salt, black pepper, and ½ cup of Parmesan cheese. Whisk well and set this mixture aside.

In a saucepan, melt the butter and sauté the minced garlic for about 20 seconds, just until fragrant.

Next, pour the creamy mixture into the saucepan and stir continuously until it starts to bubble without curdling.

Add in ½ cup of mozzarella cheese and cook for another 20 seconds, stirring until the cheese has completely melted.

Carefully pour the creamy cheese mixture over the zucchini in the dish, giving it a gentle shake to ensure even coverage.

Top with the remaining Parmesan and mozzarella cheese. Bake in the preheated oven for 18 to 22 minutes, or until the top is golden brown.

Once done, remove the dish from the oven and let it sit for 5 to 10 minutes before serving. Enjoy this comforting dish with a side salad for a complete meal!