How to Make It
Preheat oven to 450°F. Arrange bread on a baking sheet; let warm in oven 5 minutes as oven preheats.
Whisk together milk, dulce de leche, eggs, and 3 tablespoons powdered sugar in a large bowl. Stir in bread. Divide bread mixture evenly among 8 (6-ounce) ramekins, or spoon into an 11- x 7-inch baking dish. Place ramekins or baking dish on baking sheet, and bake at 450°F on top oven rack until egg mixture is set, about 20 minutes for ramekins and 20 to 25 minutes for baking dish.
Meanwhile, combine berries, vanilla, and vinegar in a bowl; let stand at least 10 minutes before serving.
Top bread pudding with strawberry mixture; dust with remaining 1 tablespoon powdered sugar.