Preheat your oven to 375°F (190°C).
Clean the mushrooms and remove the stems.
Chop the mushroom stems finely and set aside.
Heat olive oil in a skillet over medium heat. Sauté the chopped stems and minced garlic for about 3-4 minutes.
In a bowl, combine the cream cheese, Parmesan, sautéed stems, parsley, salt, and black pepper.
Fill each mushroom cap generously with the stuffing mixture.
Place the stuffed mushrooms on a baking sheet lined with parchment paper.
Bake in the preheated oven for 20-25 minutes, until golden and bubbling.
Remove from the oven and let cool for a minute before serving.