you can. just use the recipe calculator sparkrecipes.com
or look for the link in the articles and video tab. all you have to do is enter the nutrition info from the cake box as a food, add the number of servings in a box to the recipe, do the same for the soda, add the total amount of fruit that goes on the bottom, then enter how many pieces of cake the recipe yields. the program will do all the math for you.
-google first. ask questions later.