Preheat oven to 450*.Take basil leaves off of stems and add them to food processor or blender. Process until basil is minced. Set aside in bowl. Repeat the process with the sundried tomatoes, and the garlic. Add all ingredients back into food processor, with the cream cheese, and pulse quickly until mixture is blended. Alternatively, mix by hand in a bowl until cream cheese has a whipped texture and mixture is blended.Spoon mixture into mushroom caps and place on a baking sheet with sides to prevent spills in your oven.Bake for 25 minutes. Mushrooms and filling will be browned, and there will be some juice in your pan when mushrooms are done. Cool slightly before serving. Serve warm.