Take the rolls out of the pan while hot to prevent sticking to the bottom.
Unroll bread dough and roll out to make a rectangle.
With longest side facing you, sprinkle cinnamon and sugar over dough.
Roll into a log shape, using longest side. Pinch together ends and edges to seal.
Using a sharp knife, cut into 8-9 rolls and place on a parchment lined 9" round pan.
Bake at 350F for 35-40 min or until golden and baked through. Make frosting by mixing butter, cream cheese, powdered sugar and vanilla together in a bowl until smooth.
Frost once slightly cooled. Crush the remaining blackberries with a potato masher and drizzle over frosted cinnamon rolls...Best served warm.