Heat oven to 350 degrees. Spray two (9-inch) cake pans with non-stick spray.
In a large bowl, stir flour, cocoa, sugar, soda, and baking powder. In a separate bowl, beat milk, yogurt, applesauce, vanilla, egg whites and apple juice. Pour this mixture into flour mixture and beat thoroughly. Fold in chocolate chips.
Pour batter into pans and bake for 30 minutes, or until a knife tests clean when inserted in center of cakes. Cool in pans for 10 minutes, then turn out onto wire racks to cool completely.
To make frosting, beat cream cheese until fluffy, then beat in remaining ingredients; frost cake.
This is wonderful alone, but also great with vanilla ice cream.