Unwrap all the Christmas tree cakes, and set one aside for garnish.
Roughly chop the unwrapped cakes into cubes, then add them to a mixing bowl. Also add the cream cheese, milk, and vanilla extract. Using a hand mixer, whip them all together until the mixture's smooth.
Using a spatula, fold in the thawed whipped topping until evenly combined.
Transfer the dip to a serving bowl, cover, and refrigerate to chill.
When ready to serve, remove from the fridge, uncover, and top with red & green sprinkles.
Serve with a variety of dipping options- such as graham crackers, cookies, pretzels, and even fresh fruit.