Use a damp paper towel to wipe each mushroom cap to remove any dirt gently. Don’t rinse them under water, as mushrooms soak up moisture and can get watery when baked.
Carefully twist or cut the stems out of each mushroom cap without damaging the cap. Finely chop two tablespoons of the stems and set them aside for the filling. Preheat your oven to 375°F. Lightly grease a baking dish with olive oil to prevent sticking.
In a small bowl, mix melted butter, minced garlic, salt, and pepper. Brush this mixture lightly over the outside and inside of each mushroom cap. Pour any leftover butter into the bottom of the baking dish.
In another bowl, combine cream cheese, white cheddar, parmesan, chopped mushroom stems, parsley, smoked paprika, and onion powder. Stir until smooth and well combined.
Spoon or pipe the filling into each mushroom cap, mounding it slightly over the edge. Place the filled caps in the prepared baking dish. Mix panko breadcrumbs with one tablespoon of melted butter, then sprinkle a small pinch over each stuffed mushroom.
Bake: Bake on the middle oven rack for 18 to 20 minutes until the tops are golden and the mushrooms release a bit of moisture around the edges. Let the mushrooms rest for five minutes before serving. This helps the filling set so it doesn’t slide off.
