To make the tart shell: In a medium bowl, combine the flour, salt, and sugar, stirring well. Add the butter to the flour mixture and blend in with your fingers, 2 dinner knives, or a pastry blender until the mixture resembles coarse meal.

In a small bowl, beat the egg yolk with the ice water. Drizzle over the flour mixture, stirring with a fork, until it just holds together. Add a bit more water if it is too dry. Shape the dough into a ball. Flatten into a disk and place in a self-sealing plastic bag. Refrigerate for at least 30 minutes or up to 3 days.

On a lightly floured board, roll out the dough to a 10-inch-diameter round, Fit the dough into an 8-inch tart pan with a removable bottom. Run the rolling pin over the top of the pan to trim the excess dough and trim the sides even with the top of the pan. Prick the dough all over with a fork. Refrigerate for at least 30 minutes or up to 8 hours.

Preheat the oven to 350°F. Bake the shell until evenly golden brown, 20 to 30 minutes, Let cool completely in the tart pan on a wire rack. Remove from the pan.

To make the filling: Put the chocolate in a small bowl. In a small saucepan, bring the cream to a boil over medium heat. Immediately pour over the chocolate and whisk until smooth. Stir in the butter and liqueur or syrup. Pour the filling into the tart shell. Refrigerate until set, about 2 hours, or up to 2 days. To serve, decorate the top with the raspberries.