Prepare for Baking: Preheat your oven to 350°F / 175°C.
Line a large baking sheet with parchment paper for easy cleanup.
Prep the Mushrooms: Gently wipe the mushrooms clean with a damp paper towel. Carefully snap off the stems. Finely chop the stems and set them aside.
Arrange the mushroom caps on the prepared baking sheet, cavity-side up.
Cook the Filling: Heat the avocado oil in a medium skillet over medium heat.
Add the diced bacon and cook until it begins to crisp.
Add the chopped mushroom stems, green onions, and minced garlic.
Sauté for 3-5 minutes, until the bacon is fully crispy and the vegetables are tender.
Make it Creamy: Reduce the heat to low and add the cubed cream cheese to the skillet.
Stir continuously until the cream cheese is completely melted and the filling is smooth and well combined.
Remove from the heat.
Stuff the Mushrooms: Carefully spoon a generous amount of the bacon and cream cheese mixture into each mushroom cap, mounding it slightly on top.
Bake to Perfection: Bake for 25-30 minutes, or until the mushrooms are tender and the filling is hot and lightly golden on top.
Garnish with additional sliced green onions before serving, if desired.