Mix together the 1/2 cup of sugar, cinnamon and ginger in a small bowl. Set aside.
Unroll each crescent roll triangle on a smooth surface, like a cutting board.
Put 3 or 4 berries (or a few more if using blueberries, as they're smaller) on the wide end of the triangle, then roll toward the pointed end. Close up any open spaces by pinching the dough to seal, then place in cooking-sprayed baking dish in a single layer.
Melt the butter in a small saucepan, then add the 3/4 cup sugar. Mix well with a whisk, then add water. Stir until sugar is dissolved.
Pour mixture directly over the dumplings in the baking dish, then sprinkle the dumplings with a cinnamon-ginger-sugar mixture.