In a large bowl, combine flour and shortening. Using a pastry blender (see note) or fork, cut shortening in until no large pieces remain.
In a small bowl, combine egg, vinegar, and cold water. Whisk to combine.
Make wells in the flour mixture and pour the egg mixture into the wells. Stir until a soft dough is formed. Turn dough out onto a lightly floured surface and knead slightly into a ball. Cut dough in half.
Roll the first half of the dough to ¼" thickness, and cut as necessary to fit the mini pie pans (see note). Line the pie pans, taking care not to stretch the dough (as this may cause it to shrink when baked). Set lined pie pans aside.
For Filling:
Place filling ingredients in a medium bowl. Gently toss to coat.
Assembly/Baking:
Divide the filling evenly between the four mini pie pans (see note).
Roll the second half of the crust to ¼" thickness and cut as necessary to cover the top of each mini pie. You can use the remaining dough to decorate the tops of the pies as you desire.
Preheat oven to 400° F. Prepare the egg wash, and brush over the tops of each of the pies. If desired, sprinkle sugar over the top of each pie. Place the pies on a baking sheet and bake 25-30 minutes, or until the tops are golden. Place pies on a wire rack to cool.Enjoy!
Notes
Note on blackberries: I used fresh blackberries from a local farm, then froze them. You could also choose to use store-bought frozen blackberries (but I can't usually find them). I don't thaw the blackberries before using them. I've found that they have a more pleasing texture (don't get super mushy!) when they start out frozen.Note on vanilla sugar: I loooove vanilla sugar. A quick and easy way to add vanilla sweetness to anything. I purchased my vanilla sugar from Beanilla (link here), but you can make your own or substitute with sugar and vanilla extract.Note on pastry blender: While a pastry blender isn't necessary to cut in the shortening, it does make the job faster and easier. If you're looking to buy one for yourself, you can find one [here].Note on mini pie pans: I used four 5" pie pans for this recipe. If you're looking to buy some for yourself, you can find them [here]. This pie could also be made into one large (9") pie, but you would likely need more filling and a longer bake time to cook the filling through.