If bread is not stale: Preheat an oven to 400 degrees F. Spread the bread cubes out on a baking sheet and cook until toasted, about 10 minutes.
Whisk the half-and-half, eggs, sugar, whiskey, vanilla, salt and nutmeg together in a large bowl. Toss bread cubes and dried fruit together and place into the slow cooker. Pour custard over top and press down lightly until all bread is covered with custard.
Cover and cook on LOW until pudding puffs and is just set, about 3 1/2 hours. Remove insert from the slow cooker and cool on a rack, about 20 minutes.
Spoon pudding into large cups or bowls and sprinkle each serving with cinnamon sugar, and toasted nuts. Top with whipped cream or yogurt, if desired.