Preheat your oven to 190°C (375°F) and line a baking sheet with parchment paper.
Gently clean the mushroom caps with a damp cloth and carefully remove the stems, setting them aside for the stuffing.
Chop some of the stems finely and set aside. Mince the garlic and chop the parsley, then combine them with the chopped stems in a mixing bowl.
Add breadcrumbs, softened cream cheese, grated parmesan, and a drizzle of olive oil to the bowl. Mix everything until well combined and sticky.
Spoon the stuffing into each mushroom cap, pressing gently to pack it in and fill the cavity completely.
Arrange the stuffed mushrooms on the prepared baking sheet. Brush the tops lightly with olive oil for extra crispness.
Bake in the preheated oven for about 20 minutes, until the tops are golden and bubbling with aroma filling the kitchen.
Remove from the oven and let the mushrooms rest for 5 minutes, allowing the filling to set slightly.
Serve the mushrooms warm, garnished with extra parsley or a squeeze of lemon if desired.