Preheat oven to 325°F. Coat a 9x13-inch baking dish with canola cooking spray.
Mix cream cheese, vanilla, and sugar in mixer bowl on medium speed until smooth. Add the egg and egg whites (or egg substitute) and blend well. Pour into prepared baking dish.
In an 8 cup measure or similar, gently stir the blueberries into the cherry pie filling. Spread the fruit topping evenly over the cream cheese mixture in baking dish.
In same 8 cup measure, blend cake mix and yogurt with a fork (mixture will be crumbly). Spread over the fruit and cream cheese and bake for about 25 minutes. Let cool, then cover and refrigerate until ready to serve.