Preheat oven to 350°F. Spray a 9x13" pan with non-stick cooking spray and set aside.
Combine the cake mix, eggs, oil and water in a mixing bowl. Beat with an electric mixer for 2-3 minutes. Then pour into the prepared baking dish. Bake for 25-30 minutes, or until a toothpick comes clean. Let cool for 10-20 minutes after it comes out of the oven.
Whisk together the sweetened condensed milk, evaporated milk and 1/2 cup heavy cream. Once then cake has slightly cooled, poke the top with a fork, about every inch or so. The pour the milk mixture evenly over the top.
Refrigerate for at least one hour, or preferably overnight to allow the milk to soak into the cake.
To make the whipped topping, place the beaters and bowl in the freezer for a few minutes to help the peak form faster. Then beat together the cream, sugar and vanilla on high speed, until a stiff peak forms. Once the topping has thickened, spread over the cooled cake.
Sprinkle ground cinnamon on top if desired and serve with fresh strawberries, maraschino cherries or toasted coconut.