Preheat the Oven: Preheat your oven to 375°F (190°C).
Shuck the Oysters: Using an oyster knife, carefully open the oysters, removing the meat from the top shell but keeping it in the bottom half. Discard any broken shells and arrange the oysters on a baking sheet lined with parchment paper or aluminum foil for easier cleanup.
Prepare the Garlic Butter: In a small bowl, combine the melted butter with minced garlic, lemon juice, salt, pepper, and a pinch of chili flakes (if using). Stir well to combine.
Make the Topping: In a separate bowl, mix the breadcrumbs, Parmesan cheese, mozzarella cheese (if using), and chopped parsley. Pour the garlic butter mixture into the breadcrumb mixture and stir to create a moist, crumbly topping.
Top the Oysters: Spoon a generous amount of the breadcrumb mixture onto each oyster, pressing it down gently to ensure the oysters are well-covered.
Bake the Oysters: Place the oysters in the preheated oven and bake for 10-15 minutes, or until the cheese is melted, the breadcrumbs are golden brown, and the oysters are just cooked through.
Serve and Enjoy: Remove the oysters from the oven and allow them to cool for a minute. Serve immediately with lemon wedges and garnish with additional fresh parsley.