Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.

Clean the mushrooms with a damp paper towel and carefully remove the stems. Save the stems for later use.

Finely chop half of the mushroom stems and discard the rest.

In a medium bowl, combine the cream cheese, mayonnaise, chopped mushroom stems, crab meat, Parmesan, green onions, garlic, and Worcestershire sauce.

Season the mixture with Old Bay seasoning, salt, and pepper.

Fill each mushroom cap generously with the crab mixture.

In a small bowl, combine the melted butter with breadcrumbs.

Sprinkle the breadcrumb mixture over each stuffed mushroom.

Bake for 20-25 minutes, or until the mushrooms are tender and the tops are golden brown.