Bake cake according to package directions in a 9x13 pan.
While the cake is still hot, poke holes in it with a chopstick or skewer. Make a lot of holes.
Warm the hot fudge and caramel sauces in the microwave until they will pour easily (warming is more important for the fudge than the caramel).
Pour the sauces over the cake, using a spoon to evenly spread the toppings.
Cool cake completely.
Frost with frozen whipped topping.
Sprinkle with toffee chips.
Store in fridge.