Better than Sex Cake

1 (8 ounce) box devil's food cake mix
10 ounces diet cola
1 egg white
6 ounces fat-free caramel topping
7 ounces low fat sweetened condensed milk (or fat free)
1 cup heath English toffee bits
1 (8 ounce) container fat-free cool whip

Directions:
Prep Time: 10 mins
Total Time: 30 mins
1 Mix cake mix, egg white and diet soda.
2 Bake as directed in a greased 9x13 pan.
3 During the last few minutes of baking, put caramel and condensed milk in a saucepan and stir on medium low heat until smooth.
4 Take cake out of oven, and poke holes all over the top.
5 Pour caramel mixture over warm cake, filling in the holes.
6 Sprinkle Heath bits over the top, reserving some for the top.
7 Cool completely.
8 Cover with container of FF cool whip and sprinkle with remaining heath bits.
9 Put in fridge until ready to serve.