Make and bake cake as directed on package for 13x9 inch pan. Cool 15 minutes. Poke top of warm cake every ½ inch with handle of wooden spoon. (I do not use the whole can of milk on the cake.) Drizzle milk evenly over top of cake; let stand until milk has been absorbed into cake. Drizzle with caramel topping. Run knife around sides of pan to loosen cake. Cover and refrigerate about 2 hours or until chilled. Spread whipped topping over top of cake. Sprinkle with toffee chips.
Store covered in refrigerator.