Preheat the oven to 350°F. Grease a baking sheet with oil spray. Clean the mushrooms with a damp paper towel and remove the stem carefully. Then, chop the mushroom stems finely. 

In a skillet, warm the olive oil. Add the chopped mushroom stems and cook it till the moisture is out. It will become a little crispy. Now add the minced garlic and sauté for 1 minute. If you are using scallion, you can add it now and cook it till translucent. 

Add the breadcrumbs and sauté till toasted lightly. This may take 3-4 minutes. Add your choice of seasonings and herbs. Blend well. Remove from heat and let it cool slightly. 

Stir in the cream cheese and Parmesan cheese. Keep a little Parmesan cheese aside to top the stuffed mushroom. 

Spoon a generous amoung to stuffing into each mushroom cap and top it with Parmesan cheese. Place the mushroom caps on the baking sheet.

Bake the mushrooms for 20 minutes, or till they are piping hot and have liquid bubbling at the bottom of the caps. You can garnish it with herbs or serve it as is. Enjoy the cheesy goodness!