Unwrap the Christmas tree cakes and break all of them in half except one. Set the whole cake aside to decorate the top of your dip.
Place half of the cakes, the cream cheese, and the milk in a food processor. Process until smooth.
Add remaining cake halves and the vanilla and process until smooth.
Place the dip in a mixing bowl. Fold in the whipped topping.
Put the dip in a serving bowl, cover, and refrigerate until ready to serve.
Before serving place the whole Christmas tree cake on top of the dip in the middle and sprinkle with red and green sprinkles.
Serve with a variety of dippers.