For the egg whites, using a carton is easier, but you can use fresh.
For the sweetener, I like to use Trim Healthy Mama Super Sweet Blend
, so if you use a natural sweetener of some sort, check a conversion chart
Variations: Instead of making the cherries into a puree', use them whole, but change it to 2 cups. Or use 2 cups of blueberries, raspberries or strawberries.