01 -
Set oven temperature to 375°F and place rack in the middle position.
02 -
Microwave cream cheese in 20-30 second intervals until very soft.
03 -
Brown sausage in a skillet over medium-high heat, breaking it apart, until fully cooked, about 5-7 minutes. Transfer to a plate.
04 -
Reduce heat to medium, add butter to the same skillet. Once melted, sauté onions until lightly browned, approximately 5-7 minutes.
05 -
Return sausage to skillet, add minced garlic, and cook for one minute while stirring.
06 -
Remove skillet from heat. Stir in softened cream cheese until blended. Then fold in Parmesan, thyme, parsley, and breadcrumbs.
07 -
Using a spoon and hands, pack the sausage mixture tightly into mushroom caps. Arrange on a foil-lined baking sheet coated with cooking spray.
08 -
Bake uncovered for 20-25 minutes, or until mushrooms are tender and tops are golden brown. If mushrooms are large, extend cooking time slightly.