Crumble the bread into a bowl. Pour the milk over it and let stand for one to two hours. I've found that the longer it soaks in the milk, the better the end result. Preheat the oven to 325 degrees. Grease a 9-by-13-by-2-inch baking dish with 1 to 2 tablespoons of the butter.
In another bowl, beat together 3 eggs, the granulated sugar and the vanilla. Microwave the dried fruit with the 1/4 cup of Jack Daniels for one to two minutes on high, or until plumped. Drain Jack Daniels and reserve for another use, then cool fruit for a few minutes and stir in to the egg mixture, then stir the egg mixture into the bread and milk, taking care not to break up the soaked bread.
Pour into the prepared baking dish, place on the middle rack of the oven, and bake until browned and set, about 1 hour 10 minutes. Cool to room temperature.
To make sauce, stir 8 tablespoons butter and confectioners' sugar together in the top of a double boiler over simmering water until sugar is dissolved and mixture is very hot. Remove from the heat. Beat the remaining egg well and whisk it into the sugar mixture. Remove pan from base and continue beating until sauce has cooled to room temperature. Add Jack Daniels to taste (we like it pretty strong!).
To serve, preheat broiler. Cut pudding into squares and transfer each square to a heatproof serving dish. Spoon whiskey sauce over pudding and run under broiler until bubbling. Or, alternatively, you can just serve the pudding warm with the sauce spooned over. Be careful if rewarming the sauce in the microwave as you can 'scramble' the egg and the sauce turns an unappetizing grayish color and it thickens - while it still tastes great, its not very pretty.