Pastry for a 2 crust pie (I use an already pie crust, but your favorite recipe is fine)
1/2 cup sugar
1/3 cup flour
2 16 oz. bags of frozen blackberries, slightly thawed
1 teaspoon lemon juice
2 tablespoons butter
I used a 10" glass pie pan, so I reduced the oven temperature from 425 degrees to 400 degrees. If you are using a metal pie tin, preheat oven to 425 degrees.
Line pie pan with half of the pastry. Mix sugar and flour in a bowl. Add blackberries and toss gently. Put mixture in pie pan. Mound the berries in the center if it looks like they will overflow. Sprinkle lemon juice over berries. Dot with butter. Top with the other half of the pastry and crimp edges. I like to cover the edges with foil to keep the crust from getting too dark. Bake 45 to 55 minutes. Remove the foil for the last 15 minutes to allow the crust