Preheat oven to 350 degrees F (175 degrees C). Gather all ingredients.

Heat 1 tablespoon of the oil in a large nonstick skillet over medium-high. Add sausage; cook, stirring often, until browned and crumbled, about 8 minutes.

Using a slotted spoon, transfer cooked sausage to a large bowl, leaving drippings in skillet.

Return skillet to medium-high. Add remaining 1 tablespoon oil to drippings. Add mushrooms; cook, stirring occasionally, until mushrooms are softened, browned, and have released most of their liquid, 8 to 10 minutes.

Add garlic; cook, stirring constantly, until fragrant, about 30 seconds. Stir in cream cheese and Gournay cheese; cook, stirring constantly, until cheese is melted and evenly coating mushrooms, about 2 minutes.

Transfer mushroom mixture to bowl with sausage, and stir in mozzarella and 1/2 cup of the Parmesan cheese until evenly combined.

Spoon into an even layer in a 13- x 9-inch baking dish coated with cooking spray.

Stir together panko, melted butter, and remaining 1/4 cup Parmesan cheese in a small bowl. Sprinkle evenly over top of mushroom mixture.