In a large mixing bowl, beat the softened cream cheese until smooth and fluffy.
Pour in the cheesecake instant pudding mix and cold milk. Beat until thick and well combined.
Gently fold in the Cool Whip using a rubber spatula until the mixture is light and fluffy.
Stir in the mini marshmallows until evenly coated.
Carefully fold in the quartered strawberries and blueberries. Try not to mash the fruit.
Cover and refrigerate for at least 1 hour before serving. This helps the flavors come together.
Give it a gentle stir before serving and enjoy!