In a medium mixing bowl, stir together cake mix, water, oil and eggs. Beat until well combined.
Using a regular-sized muffin pan (12 cups), place cupcake liners in each cup. Spoon batter neatly into each liner until 2/3 full.
Bake for 18-20 minutes or until a toothpick inserted into the center of one cupcake comes out clean. Remove cupcakes from the pan to a wire rack and allow to cool completely.
While waiting for the cupcakes to cool, make the frosting. In a medium mixing bowl, place frosting and Cool Whip. Beat at medium-high speed until smooth and completely incorporated. Refrigerate until ready to frost cupcakes.
With a apple corer or small serrated knife (or tool of your preference), gently hollow out the center of each cupcake (make a 1-inch diameter hole in each). Spoon or pipe frosting into the holes. Then frost the tops of each cupcake.