Preheat oven to 350F. Grease muffin tins. Whisk milk, eggs, vanilla, raisins, and cinnamon in a large bowl. Add bread. Place mixture into muffin tin wells. (They puff up a bit, so do not overfill) In small bowl, cut in butter, brown sugar, flour, cinnamon, and salt until butter is pea sized. Sprinkle over top of bread mixture. Bake for 35 minutes. Let cool in pan for 5 minutes before consuming.