Preheat your oven to 375°F (190°C).
Clean the mushrooms, remove the stems, and set the caps aside. Finely chop the stems.
In a medium skillet, heat 2 tablespoons of olive oil over medium heat.
Add chopped mushroom stems, onion, garlic, and red bell pepper. Sauté until soft, about 5 minutes.
In a bowl, combine the sautéed vegetables with cream cheese, grated Parmesan cheese, and seasonings. Stir until smooth and creamy.
Brush the tops of mushroom caps with remaining olive oil.
Optionally, press heart shapes onto each cap with a cookie cutter without cutting through.
Spoon cream cheese mixture into mushroom caps and place on a baking sheet.
Bake for 15-20 minutes or until tender and tops are browned.
Serve warm.