Roll out the first half of the pie crust, line the pie plate with it, and refrigerate.
Thoroughly rinse and dry blackberries. Place blackberries in a large bowl, and sprinkle with lemon juice and vanilla.
In a separate bowl, combine the sugar, flour, cinnamon, and nutmeg. Sprinkle over the blackberries and lightly toss.
Pour the berries into the pie shell, making a slight mound in the center. Dot with butter.
Roll out the second half of the pie crust into an 11-inch circle, and cut a 2-inch cross in the center. Fold back each corner, then place over the pie filling.
Fold the edge of the top crust under the bottom crust, press together, and crimp as desired. Secure the folds with toothpicks.
Brush the top crust with the milk, then sprinkle with the 1 tablespoon of sugar (or more if desired).
Bake 40 to 45 minutes or until the crust is golden brown. Cool on a wire rack.
Recipe by Webicurean at http://blog.webicurean.com/2013/06/02/blackberry-pie-with-brandied-whipped-cream-sundaysupper/