Toffee Butterscotch Cake

Poke around 75 holes evenly over the cake's surface, poking almost to the bottom of the cake, using the blunt end of a wooden spoon after removing the cake from the oven. Set aside.
Pour the butterscotch topping and sweetened condensed milk into a medium bowl, whisk to incorporate, and then pour the mixture evenly over the cake's top. When needed, run a spatula back and forth over the cake's surface to push the mixture into the holes.
Put the cake in the fridge to cool for at least 2 hours, covered. If you'd like to bake this cake ahead of time, just remember that it will keep for a few days in the fridge.
Before serving, distribute the whipped topping evenly over the cake. Then, equally distribute the toffee pieces on top.