Put blackberries in large pot, cover with water. Add about 1 cup sugar. Bring to a boil and cook about 5 minutes. You want this to start to be a little syrupy. You can either remove the seeds now or leave them in. We actually got fancy and got them an automatic strainer that removed them.
If you removed the seeds put the pulp back in the pot with the juice and heat back up to boiling. You add the dumplings next. Now if you have a great recipe for dumplings you can use it, but we just use the one on the back of the bisquick box and dropped tablespoon size dough into the boiling blackberry mixture and reduce the heat. When dumplings are puffed and done, about 10 minutes dish up and serve hot.
Add a scoop of ice cream on top it's wonderful. I'll list the Bisquick recipe for dumplings below.
Stir 2 cups Bisquick mix and 2/3 cup milk until soft dough forms. Drop by spoonfuls into boiling mixture. Reduce heat, cook uncovered for 10 minutes.