01 -
Preheat your oven to 375°F (190°C) and lightly grease a 9×13-inch baking dish.
02 -
In a bowl, toss the sliced mushrooms with olive oil, garlic powder, thyme, salt, and pepper until well coated.
03 -
Spread the mushroom mixture evenly in the prepared baking dish.
04 -
Sprinkle the shredded cheddar and grated Parmesan over the mushrooms.
05 -
Pour the heavy cream evenly over the entire dish.
06 -
In a separate bowl, mix the melted butter with breadcrumbs until well combined. Sprinkle this mixture over the top of the casserole.
07 -
Bake in the preheated oven for 25-30 minutes, until the top is golden brown and the sauce is bubbling.
08 -
Optionally, broil for an additional 2-3 minutes to achieve an extra crispy topping.
09 -
Let the casserole rest for a few minutes before garnishing with chopped parsley and serving.