4 large eggs
1/2 cup water
1 18.5-ounce package Swiss Chocolate, devil's food, or fudge cake mix
3-4 tablespoons cocoa
Coat 2 10x15-inch jellyroll pans with cooking spray; line with wax paper, and coat with cooking spray. Set aside.
Beat eggs in large mixing bowl at medium high speed on electric mixer for 5 minutes. Add 1/2-cup water, beating at low speed just until blended.
Gradually add package of cake mix, beating at low speed just until moistened.
Beat mixture at medium high speed 2 minutes.
Divide batter in half, and spread batter evenly into prepared pans. Bake each cake at 350 degrees for 13 minutes.
Sift 1-2 tablespoons cocoa in a 10x15-inch rectangle on a cloth towel.
Repeat with a second towel.
When cakes are done, loosen and turn out immediately on prepared towel.
Peel off wax paper.
Starting at the narrow end, roll up each cake and towel together. Cool completely.
Fill cake rolls with filling mixture used on Pumpkin Roll.