6 oz (170 g) bittersweet chocolate, chopped
2 cups (500 mL) whipping cream
6 egg yolks
1/3 cup (75 mL) granulated sugar
2 tbsp (30 mL) hazelnut liqueur or almond liqueur
1 dash vanilla
1 tbsp (15 mL) chopped toasted hazelnuts
Place chocolate in heatproof bowl. In saucepan, bring 1 1/2 cups (375 mL) of the cream just to boil; pour over chocolate and stir until melted.
In separate bowl, whisk egg yolks with sugar; whisk in one-third of the chocolate mixture. Stir in remaining chocolate mixture, hazelnut liqueur and vanilla. Pour into six 6-oz (175 mL) custard cups or ramekins; place in 13- x 9-inch (3.5 L) metal cake pan. Pour in enough boiling water to come halfway up sides of cups.
Bake in centre of 325°F (160°C) oven until set around edge but still slightly jiggly in centre, about 20 minutes. Remove cups from pan; let cool on rack to room temperature. Cover and refrigerate until chilled. (Make-ahead: Refrigerate for up to 24 hours.)
In bowl, whip remaining cream. With piping bag or spoon, pipe onto centre of each serving. Garnish with hazelnuts.