Preheat oven to 375 degrees Fahrenheit.
Spread squash slices in a baking dish and place it in the oven to warm up. The squash pieces will need to be fairly warm so that the butter can be evenly distributed.
Combine bread crumbs, garlic, herbs, salt, black pepper, and 1/2 cup of the parmesan cheese in a large bowl.
Once the squash slices in the oven feel very warm to the touch, remove from the oven pour into the large bowl with the breadcrumbs.
Add melted butter and toss with wooden spoons or salad spoons until ingredients appear evenly distributed.
Pour the squash mixture into the casserole dish and then arrange the squash pieces to lay fairly flat - the pieces don't need to be perfectly flat throughout.
Evenly distribute mozzarella cheese and the rest of the parmesan over the top of the casserole.
Bake on the center rack, uncovered for 50 minutes to 1 hour, or until the melted cheese on top begins to bubble and turn golden brown on top.
Remove from the oven and allow to cool for at least 15 minutes before cutting into.
Cut into squares of desired sizes and carefully transfer to serving plates.
Garnish with fresh thyme if you like.
Enjoy!