Prepare brownies according to package directions for a 9 x 13 inch baking dish. Let cool and cut into bite-sized pieces.
In a large mixing bowl, combine Cool Whip and caramel syrup until well combined; set aside.
Cut candy bars into small pieces; set aside.
In a glass bowl or trifle bowl, layer ⅓ of the Cool Whip mixture, 1/2 brownie pieces, and ⅓ candy bars.
Repeat layers.
Drizzle chocolate and caramel syrup on top.
Notes
I would say this recipe could be made in the morning and served later that night, however, I wouldn't go more than making it a day ahead of time. However, you could prepare all the ingredients, separately, the night before, then assemble it the next day. I usually make my brownies, cut them up, slice up my snickers bar, prepare my filling, and place them all in the fridge, or aside, then assemble it an hour before my guests arrive. Store any leftovers in the refrigerator.