HEAT oven to 350° F.
COMBINE eggs, sugar, vanilla, salt, and nutmeg.
ADD milk, raisins, and butter (if using). Mix well.
STIR in bread cubes. Let stand 5 minutes or refrigerate overnight.
SPOON mixture into 8 greased (4 ounce) or 5 (8 ounce) custard cups or ramekins.
PLACE cups in a shallow baking pan. Add hot tap water to baking pan until halfway up sides of custard cups.
BAKE for about 35 minutes or until puffed and golden brown. (Add 5 to 10 minutes if refrigerated.)
SERVE warm or at room temperature drizzled with caramel topping.