The first time I had this cake [back in high school, which seems like decades ago… oh wait…] I instantly fell in love. It comes together so easily, and truly continues to get better after each day! The longer it sits, the more the caramel and sweetened condensed milk combo soaks in! I’d recommend making it at least the night before, if not even sooner!
Bake the cake according to the directions on the box.
Remove the cake from the oven and immediately poke holes all over the top using either the bottom of a thin wooden spoon, a skewer or a fork.
In a medium bowl, stir together the sweetened condensed milk and caramel sauce, then slowly drizzle the mixture all over the cake. Allow the cake to cool completely at room temperature, then refrigerate for at least 1 hour.
Spread the Cool Whip over the top of the cake, top with the Heath toffee bits and refrigerate again for at least 1 hour. Serve cold and refrigerate any leftovers. Enjoy!