In saucepan, heat sugar & water until sugar melts; set aside.
Spread berries over dough; sprinkle with cinnamon (I forgot to do this until later, but it still tasted fine).
Cut into 1/4 inch slices.
Carefully lay slices in baking dish over the butter (this is where I obviously put the cinnamon on).
Pour sugar syrup around the slices. It will be absorbed.
Bake at 350 for 45 minutes. Sprinkle the last of the sugar on top and bake for 15 more minutes.
MY REVIEW: This was delicious!!! And you probably didn't even notice the small handful of blueberries mixed in there - I didn't quite have 2 cups of blackberries. But it worked! I'd say the only downside to this dish is having to wait an hour to eat it!