Preparation Preheat oven to 350°F. Mix chocolate, hazelnuts, and brown sugar in medium bowl. Spread oats out on rimmed baking sheet. Bake until golden brown, stirring occasionally, about 7 minutes. Stir hot oats into chocolate mixture (hot oats will partially melt chocolate); set aside until chocolate firms, at least 2 hours. (Can be made 1 day ahead. Cover and chill.) Using electric mixer, beat whipping cream, crème fraîche, and sugar in large bowl until cream mixture holds peaks. Fold in whisky. In each of six 10- to 12-ounce goblets, layer 3/4 cup cream mixture and 3/4 cup oat mixture; repeat layering. Top each parfait with 3/4 cup cream mixture and sprinkle with oat mixture. Cover parfaits and chill overnight.
Preparation Preheat oven to 350°F. Mix chocolate, hazelnuts, and brown sugar in medium bowl. Spread oats out on rimmed baking sheet. Bake until golden brown, stirring occasionally, about 7 minutes. Stir hot oats into chocolate mixture (hot oats will partially melt chocolate); set aside until chocolate firms, at least 2 hours. (Can be made 1 day ahead. Cover and chill.) Using electric mixer, beat whipping cream, crème fraîche, and sugar in large bowl until cream mixture holds peaks. Fold in whisky. In each of six 10- to 12-ounce goblets, layer 3/4 cup cream mixture and 3/4 cup oat mixture; repeat layering. Top each parfait with 3/4 cup cream mixture and sprinkle with oat mixture. Cover parfaits and chill overnight.