1) Preheat oven to 350 degrees F.
2) Mix dry ingredients for crust. Cut in cold butter and water. Knead dough until it forms a ball, then refrigerate 1 hour until ready to use.
3) Roll out pie crust to ¼ inch thick. Cut crust into heart shapes, you will need an even number of hearts.
4) Fill half the hearts with a spoonful of blackberry filling. You should be able to close the hearts easily without the filling spilling out. If it does remove some of the filling.
5) Using a brush apply egg wash to rim of the heart will the filling. Top each heart with another to close the pie. Crimp the edges with a fork.
6) Brush the pies some more with egg wash, then bake for 20-25 minutes until golden brown.
7) Let the pie cool completely. Drizzle with icing before serving.