Clean the mushrooms removing all the dirt and debris. Pop of the stems and set caps aside.
In a medium bowl mix together cream cheese, sour cream , garlic powder, salt and pepper. Spoon the cream mixture into the well of each mushroom cap. Top with shredded cheese.
In a medium bowl mix together cream cheese, sour cream , garlic powder, salt and pepper. Spoon the cream mixture into the well of each mushroom cap. Top with shredded cheese.