Preheat oven to 180°C (350°F) and lightly grease a baking dish.
Spread butter on bread slices and cut them into halves or triangles.
Arrange the bread layers in the dish, optionally adding raisins between layers.
In a bowl, whisk together milk, eggs, sugar, and vanilla extract to make custard.
Pour the custard evenly over the bread and let it soak for 10 minutes.
Sprinkle a little sugar on top for a golden crust.
Bake for 30–35 minutes until the pudding is set and lightly browned.
Serve warm with cream or custard sauce if desired.