Remove cake from oven and let cool for 10 minutes after baking.
Using the end of the wooden spoon poke holes all over the top of the cake. Pour the sweetened condensed milk over the cake. This should fill in the holes and soak into the cake.
Refrigerate for 30 minutes.
Spread whipped topping over the top of the cake. Sprinkle on the toffee bits. Heat caramel in microwave then drizzle caramel over top of cake.
Refrigerate for 3-4 hours or overnight.