Preheat and prep the baking sheet: Set your oven to 400°F and lightly coat a rimmed baking sheet with oil. Put it aside for later.
Cook the bacon: Heat a skillet over medium heat and fry the bacon slices for about 3 minutes per side, until they’re crispy. Once cooked, place the bacon on a paper towel-lined plate to cool. Chop it into small pieces and set aside.
Mix the stuffing: In a medium-sized bowl, combine the softened cream cheese, Parmesan, minced garlic, parsley, salt, and pepper. Use a fork to mash and mix the ingredients until they’re smooth and fully combined. Stir in half of the bacon pieces, reserving the rest for topping.
Fill the mushrooms: Spoon approximately 2 teaspoons of the prepared cheese mixture into each mushroom cap. Arrange the stuffed mushrooms on the prepared baking sheet in an even layer. Sprinkle the remaining bacon bits on top.
Bake and serve: Bake the mushrooms in the preheated oven for about 15 minutes, or until the caps are tender and the tops are golden brown. Once baked, transfer them to a serving dish, garnish with extra parsley, and serve immediately.