01 - Beat softened cream cheese in large mixing bowl until smooth and creamy.
02 - Add powdered sugar and vanilla extract to cream cheese; beat until fully combined and fluffy.
03 - Whip cold heavy cream in separate bowl 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 combine ensuring even coating.
06 - Refrigerate at least 1 hour before serving for optimal texture and flavor development.
07 - Serve chilled; optionally garnish with additional fresh berries.