Bake the butter pecan cake according to the package directions in a 9x13-inch pan.
Once baked, let it cool for about 5 minutes, then poke holes all over the cake using a fork or the handle of a wooden spoon.
Pour the sweetened condensed milk evenly over the cake, letting it soak into the holes.
Drizzle the caramel topping all across the cake.
Allow the cake to cool completely.
Spread the whipped topping over the cooled cake.
Sprinkle the toasted pecans generously over the top.
Chill for at least an hour before serving—if you can wait that long!