Preheat your oven to 350°F (175°C).
Clean the mushrooms and gently remove the stems. Set the caps aside.
Finely chop the stems and sauté them with oil and garlic for 2–3 minutes.
In a bowl, mix the sautéed stems with softened cream cheese, Parmesan, black pepper, onion powder, and cayenne.
Fill each mushroom cap with the creamy mixture using a spoon or scoop.
Arrange the stuffed mushrooms on a baking tray.
Bake for 18–20 minutes until golden and bubbly.
Let them cool for a couple of minutes before serving hot!