Preheat oven to 350⁰F (175⁰C). Prepare a 9″ x 13″ pan.
Combine flours, baking soda and spices; stir well and set aside.
In a large bowl beat together vegetable oil, sugar, molasses and egg. Add the flour mixture alternatively with the buttermilk.
Toss the blueberries in the additional 2 tbsp. of rye flour and gently fold the blueberries into the batter. Pour the batter into the prepared pan. Sprinkle with chopped ginger pieces (optional).
Bake for about 45-50 minutes.