Heat the oven to 375 degrees and line a baking sheet with parchment paper.
Wipe the mushrooms clean with a damp cloth. Twist off the stems and set the caps aside.
Finely chop the mushroom stems and place them in a mixing bowl with the cream cheese, parsley, chives, garlic, Parmesan, salt, and pepper. Stir until the mixture is smooth and evenly combined.
Brush the outside of each mushroom cap lightly with olive oil. Arrange the caps on the prepared baking sheet with the open side up.
Spoon the cheese filling into each cap, mounding it slightly on top.
Bake for 18 to 20 minutes until the mushrooms are tender and the filling is lightly golden on top. Let them cool for a few minutes before serving.