Plum Pie with Streusel Topping

Ingredients

Dough:
  1 1/3 cups flour
  1 stick butter (cut in 8 chunks and freeze ahead of time)
  1/4 cup ice water
Filling:
  5-6 cups plums (fresh or frozen)
  1/3 cup sugar (more if you like sweet)
  1.5 tablespoons cornstarch
  1 tablespoon lemon juice
Topping:
  1/2 stick butter, slightly softened
  1/4 cup brown sugar
  1/4 cup flour
  1/2 cup chopped walnuts

Make Filling:

  Pit plums. Half or dice and toss with sugar, cornstarch, and lemon juice.

Make Topping:

  Combine dry ingredients in a bowl or Cuisinart, then cut or pulse in butter.

Preheat oven to 425°F.

Pastry dough:

  Put flour & sugar into Cuisinart bowl. 
  Add frozen butter chunks and start processing. 
  As soon as the butter chunk noise settles down, pour the ice water into the feed tube. 
  Let the processor run until the dough forms into a ball and rolls around the inside of the bowl, cleaning the sides.

On a lightly floured surface roll dough into a 15-inch round.
Lay dough in a No. 8 cast-iron skillet, overhanging the rim. 
Spoon plum filling into shell. 
Crumble topping over the filling. 
Fold pastry over filling, leaving center uncovered.  

Bake pie at 425°F in middle of oven for 25 minutes
Turn oven down to 350°F and bake 25 more minutes. 

Serve warm or at room temperature.