PreparationFor sauce: Cook first 3 ingredients in heavy small saucepan over medium heat, stirring until sugar dissolves. Add chocolate and stir until melted. (Can be made 3 days ahead. Cover; chill. Before using, rewarm over low heat just until liquid.) For soufflés: Preheat oven to 375°F. Butter and sugar six 2/3-cup soufflé dishes. Whisk yolks, brown sugar and flour in medium bowl. Bring milk to simmer in heavy medium saucepan. Gradually whisk hot milk mixture into yolk mixture. Return mixture to saucepan and whisk constantly over medium heat until mixture is very thick, about 2 minutes. Transfer mixture to large bowl. Whisk in butter and Scotch. Cool to lukewarm. Using electric mixer fitted with clean dry beaters, beat whites in large bowl to soft peaks. Gradually beat in 1/4 cup sugar and continue beating to stiff peaks. Gently fold 1/4 of whites into soufflé mixture to lighten. Fold in remaining whites. Gently fold in 3/4 cup chopped toffee. Divide mixture among prepared dishes. Smooth tops. Bake until soufflés puff and tops are golden, about 12 minutes. Transfer to plates. Sprinkle with remaining 1/4 cup toffee. Serve with sauce.
PreparationFor sauce: Cook first 3 ingredients in heavy small saucepan over medium heat, stirring until sugar dissolves. Add chocolate and stir until melted. (Can be made 3 days ahead. Cover; chill. Before using, rewarm over low heat just until liquid.) For soufflés: Preheat oven to 375°F. Butter and sugar six 2/3-cup soufflé dishes. Whisk yolks, brown sugar and flour in medium bowl. Bring milk to simmer in heavy medium saucepan. Gradually whisk hot milk mixture into yolk mixture. Return mixture to saucepan and whisk constantly over medium heat until mixture is very thick, about 2 minutes. Transfer mixture to large bowl. Whisk in butter and Scotch. Cool to lukewarm. Using electric mixer fitted with clean dry beaters, beat whites in large bowl to soft peaks. Gradually beat in 1/4 cup sugar and continue beating to stiff peaks. Gently fold 1/4 of whites into soufflé mixture to lighten. Fold in remaining whites. Gently fold in 3/4 cup chopped toffee. Divide mixture among prepared dishes. Smooth tops. Bake until soufflés puff and tops are golden, about 12 minutes. Transfer to plates. Sprinkle with remaining 1/4 cup toffee. Serve with sauce.