01 - Combine flour, sugar, and salt in a bowl. Cut in cold butter until mixture resembles coarse crumbs. Add egg yolk and 1-2 tablespoons cold water, mixing just until dough forms a ball. Flatten into a disk, wrap in plastic, and refrigerate 30 minutes.
02 - Roll dough on lightly floured surface to fit 9-inch tart pan. Press dough into pan, trimming excess. Prick base thoroughly with fork.
03 - Freeze crust 10 minutes. Preheat oven to 375°F. Line crust with parchment paper, fill with pie weights. Bake 15 minutes, remove weights and paper, bake 5 additional minutes until golden. Cool completely.
04 - Heat cream in small saucepan until simmering. Pour over chopped chocolate in bowl. Let stand 1 minute, add butter, stir until smooth and glossy.
05 - Pour ganache into cooled crust. Smooth top. Refrigerate 45-60 minutes until set but slightly soft.
06 - Arrange raspberries over ganache. Warm raspberry jam with water, brush gently over berries for glossy finish. Serve chilled or at room temperature.