Preheat the oven to 350 degrees. Grease a 9x13-inch baking dish with nonstick cooking spray.
In the bowl of a food processor fitted with a metal blade, place the flours, sugar, oats, 1 teaspoon of the cinnamon, the ginger, salt, and butter cubes. Pulse until coarse crumbs are formed. Alternatively, you can place the ingredients in a large mixing bowl and cut the butter in with a pastry blender or two knives.
Remove one cup of the crumb mixture and place in a small mixing bowl. Add another 1/2 teaspoon cinnamon to the crumbs and set aside.
To the mixture in the food processor, add the baking powder, baking soda, buttermilk, and egg. Pulse until a thick batter forms.
Spread the batter in the prepared baking dish. Sprinkle the berries across the top. Sprinkle the reserved crumb mixture over the berries. Bake for about 35 minutes or until the cake is golden and cooked through. Cool on a rack. Serve warm or at room temperature.
Store coffeecake, covered in plastic wrap or foil, at room temperature for 1- 2 days.