Blueberry Pie

2 batches basic pie dough, or 2 purchased 9-inch pie shells

4 cups fresh or frozen blueberries 

1 Tbs. fresh lemon juice 

1/2 tsp. vanilla extract 

1/2 cup plus 1 Tbs. sugar 

3 Tbs. all-purpose flour 

Pinch of kosher salt 

4 Tbs. (1/2 stick) cold unsalted butter, cut into small chunks 

2 Tbs. milk 

Vanilla bean ice cream, homemade or purchased, for serving