Wipe mushrooms clean with a damp cloth and remove the stems. Finely chop the stems and reserve.
In a large mixing bowl, combine 3 tablespoons teriyaki sauce with the olive oil. Add the mushrooms, toss to coat, and let sit.
Preheat oven to 325 degrees. Line baking sheet with parchment paper.
In a large skillet, cook the sausage over medium heat until browned and fully cooked. Add the chopped mushroom stems, green onions, and remaining 1 tablespoon of teriyaki sauce. Cook, stirring occasionally, for 3-4 minutes. Add the cream cheese and cook, stirring, until the cheese is fully melted. Stir in the bread crumbs.
Stuff the mushroom caps with the sausage mixture. Place on prepared baking sheets and bake for 35 minutes. Serve hot.