To begin, cleanse the mushrooms using a moist paper towel (refer to Note 1). To eliminate the stems, pinch them. Preheating the oven to 400°F is required. Oil a rimmed baking sheet lightly before setting it aside.
Cook the bacon in a large skillet over medium heat for approximately 3 minutes per side, or until browned and golden. Place the bacon on a plate lined with paper towels to chill. Set aside the tiny pieces that have been chopped.
Combine the filling ingredients (cream cheese, Parmesan, garlic, parsley, salt, and pepper) in a medium basin. After mashing and mixing the ingredients with a fork, add half of the bacon pieces. Stirring should continue until incorporated. Apply the filling to the mushrooms in an even distribution, utilizing a small cookie tablespoon or approximately 2 teaspoons of stuffing per mushroom. The remaining bacon pieces should be sprinkled on top.
Bake the mushrooms for 15 minutes, with the tops beginning to brown in spots, after arranging them evenly dispersed on the prepared baking sheet. Serve the mushrooms adorned with additional parsley after transferring them to a serving platter.