Preheat your oven to 375°F (190°C).
Clean the mushrooms by gently wiping them with a damp paper towel. Remove the stems and set the mushroom caps aside.
In a skillet, melt butter over medium heat. Add minced garlic and cook until fragrant, about 1 minute.
Add the chopped shrimp to the skillet and cook until they turn pink, around 3-4 minutes. Remove from heat.
In a bowl, mix the shrimp, cream cheese, breadcrumbs, parsley, and Parmesan (if using). Season with salt and pepper to taste.
Spoon the mixture into each mushroom cap, packing the stuffing in.
Arrange the stuffed mushrooms on a baking sheet and bake for 15-20 minutes, or until the mushrooms are tender and the stuffing is golden.
Serve hot and enjoy your Shrimp and Garlic-Stuffed Mushrooms!