Heat oven to 350°F. Lightly brush a baking dish or mini baking dishes with melted butter.
In a small saucepan, warm milk, butter, vanilla, sugar and salt. Continue cooking just until the butter melts. Cool slightly.
Add the bread cubes to the baking pan/ pans.
Add the eggs to the cooled milk mixture and whisk until well combined.
Pour the custard over the bread.
Bake for 30~45 minutes or until the custard is set and the edges of the bread have browned.
Serve warm or at room temperature.