Wash the mushrooms and pat dry with paper towels. 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, crushed red 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.

Remove from oven and let cool for 5 minutes.

Serve stuffed mushrooms on a decorative serving platter.