Prepare the vanilla pudding mix according to package directions and allow it to set up in the refrigerator.
Using an electric mixer, cream together cream cheese and powdered sugar until nice and smooth.
In a large bowl, fold/stir together the cream cheese mixture, pudding (that has set up completely), and whipped topping.
Add in all of the berries and fold gently.
Cover and store in the refrigerator until ready to serve. When ready to serve, fold in the marshmallows.
**This salad is best if served within a few hours of being made. The juices from the berries make the mixture soupy the longer it sits. The marshmallows will start to dissolve if you add them in too soon, so wait until ready to serve.