Preheat oven to 375°. Pour 1/4 cup bourbon over raisins in a small bowl; let stand 5 minutes. Place bread in a greased 8-in. square baking dish. Top with walnuts, raisins and soaking liquid., In a large bowl, whisk eggs, cream, sugar, cinnamon, vanilla, nutmeg, salt and remaining bourbon until blended. Pour over bread; let stand until bread is softened ,about 15 minutes. , Bake, uncovered, until puffed, golden and a knife inserted in the center comes out clean, 35-40 minutes. Serve warm. If desired, serve with confectioners' sugar and whipped cream.