Line pie pan with pastry; set in refrigerator until chilled. Turn strawberries into chilled pastry shell. Blend next three ingredients together; gradually add to sour cream, mixing well.
Spoon sour cream mixture over strawberries and sprinkle with remaining sugar. Bake at 450 degrees for 10 minutes. Reduce heat to 350 degrees and bake 30 minutes longer, or until topping is lightly browned. Remove to cooling rack. Cool.