Start by preheating your oven to 375°F (190°C).
Clean the mushrooms, remove the stems, and finely chop them. Set the mushroom caps aside.
In a frying pan, melt the butter over medium heat. Add the minced garlic and chopped mushroom stems. Sauté until the mushrooms release their moisture and the mixture becomes fragrant.
Stir in the crab meat, breadcrumbs, half of the grated Parmesan cheese, and half of the chopped parsley. Season with salt and pepper to taste. Cook for an additional 3-4 minutes, or until the mixture is well combined.
Using a spoon, generously fill each mushroom cap with the crab mixture, piling it up. Place the stuffed mushrooms on a baking sheet.
Sprinkle the remaining Parmesan cheese and parsley over the stuffed mushrooms.
Bake in the preheated oven for about 15-20 minutes or until the mushrooms are tender, and the tops are golden brown.
Once they're done, remove the mushrooms from the oven and let them cool for a few minutes.