Prepare cake mix as directed on package and bake. Prepare vanilla pudding mix and combine with whipped topping. After cake has baked and cooled, crumble half the cake in a large bowl. Spread half the pudding/whipped topping mixture on the cake. Pour half the toffee bits on the pudding, then repeat the whole process starting with the cake then pudding and toffee. Top with nuts if desired. Eat and Enjoy.