Preheat oven to 350 degrees F.
Heat butter, sugar, and water in a large saucepan over low heat. Add chocolate chips and stir until melted.
Add dry ingredients and beat in eggs. Drop by teaspoon onto cookie sheet. Bake for 10-14 minutes. After cookies have cooled, sandwich 2 cookies together with cream filling.
for cream filling:
Blend 1 cup powdered sugar with butter. Beat in remaining powdered sugar and blackberry puree alternately. Use your judgement and don't add all the puree at once. You want the filling to be able to hold it's thickness. More puree will make it thinner. More powdered sugar will make it thicker.