Preheat oven to 350 degrees F. Prepare and roll out Rich Tart Pastry. Line a 10-inch tart pan with a removable bottom with pastry. Ease pastry into pan, being careful not to stretch pastry. Press pastry into fluted sides of tart pan; trim edges. Set aside.
For filling, in a large bowl slightly beat eggs with a fork. Stir in sugar, flour, and, if using, liquid vanilla; set aside.
In a medium heavy saucepan combine the vanilla bean, if using, and butter. Cook over medium-high heat until the butter turns the color of light brown sugar. Remove from heat. Remove and discard vanilla bean. Slowly add the browned butter to the egg mixture, stirring until combined. Pour into the pastry-lined tart pan.
Bake about 35 minutes or until the top is crisp and golden. Cool 1 to 2 hours in pan on a wire rack. Refrigerate within 2 hours; cover for longer storage.
To serve, remove sides of the tart pan. Cut tart into wedges. Place wedges on individual dessert plates. Serve with assorted mixed berries and, if desired, whipped cream.
Makes 12 slices.
Rich Tart Pastry
In a medium bowl, stir together flour and sugar. Using a pastry blender, cut in cold butter until pieces are pea size. In a small bowl stir together egg yolks and ice water. Gradually stir egg yolk mixture into flour mixture. Using your fingers, gently knead the pastry just until a ball forms. Cover pastry with plastic wrap and chill for 30 to 60 minutes or until pastry is easy to handle.