Remove cool whip from freezer to thaw on counter.
Mix and bake brownies, or purchase pre-made brownies from the grocery store. Crumble brownies once cooled.
Mix vanilla and chocolate pudding together and add 4 cups of cold milk. Use a wire whisk to combine thoroughly. The mixture will be soft set and ready to use immediately.
Start layering in this order: 1. Crumbled brownie; 2. Pudding mixture; 3. Cool Whip. Repeat until all ingredients have been added.
Cover and refrigerate overnight for best results.