Combine the 1/3 cup of sugar, cornstarch, salt, and cinnamon with the syrup (no more than 1 cup) drained from the blackberries. Cook in a saucepan over medium heat until smooth and thick, stirring constantly. Add 1 cup of thickened sauce slowly to egg yolks, and then whisk egg yolk mixture back into remaining sauce. Bring to boil, reduce heat, and simmer for two minutes. Remove from heat and then add berries, lemon juice, and butter. Pour into pastry shell. Beat egg whites until soft peaks form. Continue beating, adding sugar one tablespoon at a time until stiff peaks form. Spread over filling and bake in low oven (350 degrees) for 15 minutes or until well browned. Blueberries, strawberries, gooseberries, or loganberries may be substituted.

* I brought 3 1/2 cups of loosely packed frozen blackberries to a boil with /34 cups of water. I simmered this for 10 minutes, added 1 cup of sugar, brought back to the boil and then simmered briefly again.