PUDDING: Beat eggs in a large bowl. Add milk and beat again. Stir in pumpkin, sugar, cinnamon, nutmeg, salt and vanilla. Add bread pieces and press with your hands to submerge bread in the milk mixture. (If you have the time, cover and refrigerate the mixture several hours or overnight; break up the bread the next day and bake as directed; if not, proceed as follows.) Set the mixture aside for 15 minutes. Use your fingers to break up the chunks of bread. Set aside 15 minutes and repeat. Add raisins. Heat oven to 350 degrees. Generously butter a 2 quart baking dish. Fill the dish with bread pudding mixture and bake for 1 hour, or until pudding is set. Serve warm, hot or cold with hot bourbon sauce.
BOURBON SAUCE: Use unsalted real butter for the best bourbon sauce; margerine doesn't make a great sauce. Melt butter in a bowl set over hot but not boiling water. Combine egg, sugar and milk in a small bowl and beat until light colored. Add to butter and beat with a whisk over hot water until sugar dissolves - at least 5 minutes. Add boubon and stir. Remove from stove and serve.