1. In a food processor, pulse flour, powdered sugar, and salt. 2. Add cold butter and pulse until mixture resembles coarse crumbs. 3. Add egg yolk and 1–2 tbsp cold water, pulsing just until dough comes together. 4. Wrap in plastic and chill for 30 minutes. 5. Roll out dough and press into small tartlet pans; prick bottoms with a fork. 6. Blind bake at 350 °F (175 °C) for 15 minutes with parchment and baking weights. Remove weights and bake 5 more minutes until golden. Let cool completely.

1. Heat milk in a saucepan until steaming (not boiling). 2. In a bowl, whisk egg yolks, sugar, and cornstarch until smooth. 3. Gradually whisk in the hot milk, then return the mixture to the saucepan. 4. Cook over medium heat, stirring constantly, until thickened. 5. Remove from heat and stir in butter and vanilla. Cool completely.

1. Spoon or pipe cooled custard into tart shells. 2. Pipe whipped cream rosettes around the edges. 3. Arrange grapes in small clusters on top, leaving stems for a natural look. 4. Garnish with edible flowers or mint leaves if desired. 5. Dust lightly with powdered sugar before serving.