Preheat your oven to 350ºF. Prepare mushrooms by removing stems and discarding.
In a large bowl mix together the cream cheese, spinach, half of the parmesan, paprika, salt, and pepper. Spoon into the mushroom caps, rounding slightly. Place mushrooms on a sheet pan.
In a small bowl mix together the remaining cheese, panko, and melted butter. Sprinkle mixture on mushrooms. Bake until heated through, about 20 minutes. Serve warm.
Look for large mushroom caps for this recipe.
Eat these mushrooms immediately for the best taste.
Serve this Stuffed Mushrooms with Spinach with Pomegranate Guacamole for appetizers.