Place the pudding mix and cold milk in a medium-sized bowl, whisk for 2 minutes until it starts to thicken. Place in the refrigerator for 5 minutes.
Spread 1/4th of the cool whip on the bottom of a 9x13 baking dish.
Layer the cut swiss rolls on top (cut side up), gently pressing them into the cool whip, this will help the cake to stabilize. Add a row of the swiss rolls around the edge of the baking dish, cut side out. I like to use a clear glass baking dish because you can see the pretty rolls from the outside.
In a medium-sized bowl, stir together another 1/4th of the cool whip with ⅓ of the chocolate pudding until smooth.
Spoon this on top of the swiss rolls and smooth out the top.
Add another layer of swiss rolls, cut side up. Gently press them down.
Add the remaining chocolate pudding on top and smooth it out.
Add another layer of swiss rolls, cut side up, there should be none left after this. Gently press them down.
Top with the remaining cool whip, and smooth it out. Cover with plastic wrap and place in the fridge for at least 6 hours to set or even better overnight.
Garnish with more swiss rolls or some of the chocolate that flakes off the swiss rolls while cutting them.
Notes
If you want to substitute the pudding for a different flavor, see some ideas above.
This needs to chill at least 6 hours if not overnight for best results.