In a large bowl, stir together 2 1/2 cups Oreos and butter, until well combined.

Press mixture evenly and firmly into the botton of springform pan.

Freeze crust for at least 20 minutes.

In a large bowl combine cream cheese, powered sugar, cake mix and milk (if needed).

Fold in Cool Whip and vanilla extract.

Fold in crushed Oreos and rainbow sprinkles.

Give it a taste, add more sugar (if desired).

Pour into prepared pan and spread into an even layer.

Freeze for 2-3 hours or refrigerate overnight, or until set.

Decorate as desired.

If completely frozen, allow to sit at room temperature to soften up a bit before cuttng.