01 - Beat softened cream cheese in large mixing bowl until smooth and creamy.
02 - Add powdered sugar and vanilla extract; beat until fully incorporated and fluffy.
03 - In separate bowl, whip cold heavy cream until stiff peaks form.
04 - Gently fold whipped cream into cream cheese mixture until smooth and uniform.
05 - Add strawberries, blueberries, and mini marshmallows; fold gently to coat evenly.
06 - Refrigerate at least 1 hour for optimal texture and flavor development.
07 - Serve chilled; garnish with additional berries if desired.