In a food processor, pulse the all-purpose flour, powdered sugar, and salt until combined. Add the cold, cubed butter and pulse until the mixture resembles coarse sand. Add the egg yolk and ice water, pulsing just until the dough clumps together.

Shape the dough into a disc, wrap in plastic, and chill for 1 hour. Roll out on a floured surface into an 11-inch (28cm) circle. Press into a 9-inch (23cm) fluted tart pan, trimming excess edges.

Prick the bottom of the dough with a fork, line with parchment paper, and fill with pie weights. Bake at 375°F (190°C) for 15 minutes. Remove weights and bake another 10-12 minutes until a baked golden-brown fluted tart shell forms. Let cool completely.

Place chopped dark chocolate in a bowl. Heat heavy cream in a saucepan until simmering (do not boil). Pour over the chocolate and let sit for 5 minutes.

Gently whisk the chocolate and cream starting from the center. Add the room-temperature butter and whisk until you achieve a dark, glossy, thick chocolate ganache.

Pour the warm ganache into the cooled golden-brown tart shell. Smooth the top. While still wet, tightly pack the fresh bright red whole raspberries bottom-down until the surface is entirely covered.

Refrigerate for at least 2 hours to allow the ganache to set completely firm.

Just before serving, sprinkle a very light dusting of white powdered sugar over the raspberries. Place two small fresh green mint leaves resting near the center. Slice with a hot, clean knife.