Step 1

Preheat your oven to 350 degrees F. Lightly grease or spray a 2-quart casserole dish or 9x13-inch baking pan with non-stick cooking spray.

Step 2

Wash and thinly slice the yellow squash. Place the slices into a large mixing bowl.

Step 3

In a medium mixing bowl, combine the sour cream, eggs, fresh thyme, salt, and pepper. Fold in grated cheese then pour over the sliced yellow squash. Mix to combine.

Step 4

Transfer the squash and cheese mixture into the prepared baking dish.

Step 5

In a small bowl, combine panko breadcrumbs with the melted butter and garlic salt, plus parmesan and fresh parsley if desired. Sprinkle the topping mixture over the squash in your baking dish, then transfer to the center of the middle rack in your preheated oven.

Step 6

Bake for 30-35 minutes or until the cheese is melted and starting to bubble and the topping is lightly golden brown in color. You can also broil on low for the last few minutes to finish browning the panko topping.

Step 7

Remove from the oven and serve immediately.