01 - Preheat oven to 350°F. Line a baking sheet with parchment paper.
02 - In a mixing bowl, combine flour, powdered sugar, and salt. Cut in cold butter until mixture resembles coarse breadcrumbs. Add egg yolk and 2 tablespoons cold water, mixing until dough forms. Add additional water as needed. Shape into a rectangle, wrap in plastic wrap, and refrigerate for 20 minutes.
03 - Roll dough to 1/4 inch thickness into approximately 9 by 12 inch rectangle. Trim edges for clean presentation. Transfer to prepared baking sheet. Pierce with fork. Bake 20 to 25 minutes until golden brown. Cool completely before filling.
04 - Heat milk with vanilla bean in saucepan until simmering. In separate bowl, whisk egg yolks with sugar and cornstarch until smooth. Gradually pour hot milk into egg mixture while whisking constantly. Return combined mixture to saucepan over medium heat, whisking continuously until thickened, approximately 3 to 4 minutes. Remove from heat, discard vanilla bean, and stir in butter. Allow to cool to room temperature.
05 - Spread cooled vanilla custard evenly across cooled pastry base, creating uniform layer.
06 - Arrange fresh fruits atop custard in love letter or envelope shape. Use strawberries to form envelope flap and remaining fruits for artistic embellishment.
07 - Heat apricot jam with water in small saucepan until liquefied. Strain through fine mesh. Gently brush glaze over fruit arrangement to achieve glossy appearance.
08 - Refrigerate finished tart minimum 30 minutes before portioning and presenting.