3 TBSP butter or margarine, softened plus more for spreading o the bread
1 loaf of rich egg bread (such as challah), cut into 1-inch-thick slices
2½ cups whole milk
3 large eggs
¼ cup brown sugar
1 tsp cinnamon
1 tablespoon vanilla extract
¾ teaspoon salt
3 ounces dark chocolate, coarsely chopped
Grease shallow 3-quart ceramic baking dish. In microwave-safe small bowl, reserve 2 tablespoons dulce de leche; cover and refrigerate. Lightly butter both sides of all bread slices. In 12-in. skillet, cook bread slices on medium-high 1 to 2 minutes per side or until golden brown and toasted. Cool on wire rack. In same skillet, combine milk, butter and remaining dulce de leche. Heat on medium-high 6 to 8 minutes or until bubbles form around edge of pan, stirring occasionally. Meanwhile, in large bowl, with wire whisk, combine eggs, brown sugar, cinnamon, vanilla, and salt. Continue whisking and add ½ cup hot milk mixture in slow, steady stream. Whisk in remaining milk mixture. Cut toasted bread slices into 1-in. cubes; arrange in single layer in prepared baking dish. Sprinkle with even layer of chocolate. Pour egg mixture over bread and chocolate. Let stand at least 30 minutes or overnight. Preheat oven to 350°F. Bake 25 to 30 minutes or until just set and dark golden brown on top. Cool bread pudding in pan on wire rack 20 minutes. Microwave reserved dulce de leche on High 20 seconds to warm. Drizzle over bread pudding to serve.