Preheat oven to 350 degrees F. Spray 8 (4-inch) ramekins with butter flavored cooking spray and set aside.
In a bowl combine thawed blackberries, tapioca, lemon juice, 1/4 cup of cream soda and sugar. Transfer to ramekins.
In a large bowl combined biscuit mix and remaining cream soda. Mix until well blended. Sprinkle biscuit mix over berries. Dust with sugar. Bake for 30 to 40 minutes. Serve warm.
Recipe courtesy of Sandra Lee, 2008