4. Roll out second pie crust.
5. Using a star-shaped cookie cutter, cut out stars from pie crust.
6. Pour blackberry mixture into waiting pie crust. Dot with butter or margarine.
7. Place stars on top of blackberry mixture. Place them to the edge of the pie and slightly overlap the stars until the top is covered. Dust with sugar, if desired.
8. Bake at 400F for about 50 minutes or until blackberry mixture is bubbly and crust is golden.