4 tbs cornstarch
3 cups sugar
2 tbs lemon juice
8 cups blackberries
2 cups flour
2 tsp baking powder
1 tsp salt
12 tbs margarine, softened
In a medium pot, stir together the cornstarch and 1/2 cups cold water until cornstarch is dissolved. Add 2 cups sugar, lemon juice, and blackberries. Stir well. Transfer to a large skillet. In a large pot, combine 1 cup sugar, baking powder, flour, and salt. Blend in margarine until mixture resembles coarse meal. Add 1/2 cups boiling water and stir until it forms a dough. Bring the blackberry mixture to a boil. Stir often to prevent scorching. Drop dough by spoonfuls onto the mixture.
Remove form stove and bake in cardboard oven at 400 for 20-25 minutes.