In a large bowl, blend sugar, cinnamon, and nutmeg. Whisk in eggs, milk, cream, and vanilla.
Tear bread slices into big, bite size pieces; place in a lightly buttered 9x13x2 inch pan.
Pour custard mixture over bread and allow to soak until soft, about 1 hour. Stir raisins into pudding. Top with nuts.
Bake uncovered 1 ½ hours.
Prepare Rye Whiskey Sauce; reserve, keeping warm until needed.
Scoop bread pudding into individual bowls and top with reserved Rye Whiskey Sauce.
Rye Whiskey Sauce
Stirring occasionally, heat cream and sugar in a heavy-bottomed medium saucepan over medium-high heat until mixture begins to boil.
Mix cornstarch and cold water in small bowl until smooth; slowly whisk into simmering cream. Simmer 2 to 3 minutes.
Put yolks into a stainless steel bowl; whisk. Temper yolks by slowly whisking 1 cup hot, thickened cream mixture into yolks. Return yolk mixture to hot cream mixture, whisking in slowly. After mixture is whisked together, cook over medium-low heat until mixture reaches 140 degrees. Remove from heat and pour through a fine mesh strainer.
Add whiskey, adjusting to taste, and keep warm until ready to use.
Store sauce in a covered container in refrigerator up to 3 days.