1.Preheat oven to 350 degrees.
2.Place frozen fruit ( remember, don’t thaw) in the bottom of a round or square glass or ceramic baking dish (about 8 or 9 inches) that has been lightly misted with cooking spray. Set aside for just a few minutes.
3.In a mixing bowl, add the half box of cake mix and about 6 to 7 ounces of seltzer and gently mix together. If you are using the vanilla, this is the time to add it.
4.Pour mixture over the frozen fruit. Bake uncovered on the top rack of your oven for about 30 to 40 minutes or until golden brown. You may see the fruit bubbling a little too.
5.Let cool slightly for just a few minutes and dig in!
Recipe Note: Great with vanilla ice cream and whipped cream!