Remove the stems and set aside (they can be minced and added to the sausage mixture later is desired).
Preheat oven to 350.
Cook and crumble the sausage in a large skillet until done, drain, and place in a mixing bowl. Add the cream cheese, jack cheese, Ghost Pepper Flakes and minced stems if desired. Mix well.
Place 1 heaping teaspoon of the mixture into each mushroom cap.
Place the stuffed mushroom caps on a rimmed baking pan, sprinkle with parmesan, and bake for 20 minutes.
