Lightly coat a 2-quart rectangular baking dish with nonstick cooking spray; set aside. In a large bowl stir together pastry flour, cornmeal, granulated sugar, 1 teaspoon of cinnamon, baking soda, ginger and salt.
In a medium bowl whisk together yogurt, egg, oil, applesauce and butter flavoring until well mixed. Add egg mixture to the flour mixture; stir just until combined. Spread half of the batter into the prepared dish.
Sprinkle with 1 cup of frozen blueberries. Top with the remaining batter; spread evenly. Cover and chill in the refrigerator for 8 to 24 hours.
Allow the coffee cake to stand at room temperature while the oven preheats to 350°F. In a small bowl mix together the remaining 1 cup of frozen blueberries, brown sugar and the remaining ½ teaspoon of cinnamon; sprinkle on top of the batter. Bake, uncovered, about 35 minutes or until a toothpick inserted near the center comes out clean. Serve warm. If desired, serve with whipped topping and sprinkle with additional ginger.
Tip: If using a sugar substitute, choose from Splenda® Granular or Sweet'N Low® bulk or packets for the granulated sugar. Choose Splenda® Brown Sugar Blend for the brown sugar. Follow package directions to use product amounts equivalent to ⅓ cup granulated sugar and 2 tablespoons packed brown sugar. Nutrition Per Serving with Substitute: same as below except 152 calories, 19 g carbohydrate, 5 g sugar. Exchanges: 0 other carb. Carb choice: 1