Preheat oven to 400 degrees F/200 degrees C. Have ready an 11-inch tart pan with removable bottom.
In a food processor blend together flour, sugar, salt and butter until mixture resembles fine meal. Add egg yolk and pulse until dough begins to come together but is still crumbly.
Press dough evenly onto bottom and up sides of tart pan. Prick bottom of crust all over with a fork and chill 30 minutes.
Bake crust in middle of preheated oven for 20 to 25 minutes, or until golden. Cool in pan on a wire rack.
In a small bowl sprinkle gelatin over water to soften.
In a saucepan combine lemon juice, sugar, cinnamon, a pinch salt and 3 cups blueberries and simmer, stirring occasionally, 10 minutes. Remove pan from heat and stir in gelatin mixture and vanilla.
Transfer blueberry mixture to a metal bowl set in a bowl of ice and cold water and stir until thickened to the consistency of raw egg white but not set, about 15 minutes. Fold in remaining 5 cups blueberries and pour filling into crust, spreading evenly. Chill tart, covered loosely, at least 4 hours, or until set, and up to 1 day.
Cut tart into wedges and serve with sweetened whipped cream.
Makes 8 to 10 servings.
Date: September 26, 2006