Ingredients

1 cup whole milk

1 1/2 sticks unsalted butter, cut into small pieces, plus more for bowl

1/2 cup granulated sugar

1 tablespoon pure vanilla extract

1/2 teaspoon salt

4 1/2 cups all-purpose flour, divided, plus more for surface

2 1/4 teaspoons (one 1/4-ounce envelope) active dry yeast

3 large eggs plus 1 large egg yolk

1/3 cup packed light-brown sugar

1 cup golden raisins

6 ounces bittersweet chocolate, finely chopped

3 tablespoons unsalted butter, melted

Confectioners’ sugar, for dusting

Preparation

Dough: Bring milk almost to a boil in a saucepan. Remove from heat, and stir in butter, granulated sugar, vanilla, and salt. Transfer to a large bowl, and let cool until lukewarm, 3 to 5 minutes. Add 1 1/2 cups flour and the yeast, and beat with a mixer on low speed. Beat in eggs and egg yolk, 1 at a time. Beat in remaining 3 cups flour, 1/2 cup at a time. Transfer dough (it will be sticky) to a lightly floured surface, and knead until smooth, about 5 minutes. Place in a buttered bowl, and turn to coat. Cover with plastic wrap, and let rise in a warm place until doubled, about 1 hour. Punch down dough, knead a few times, and let rest 10 minutes. Roll out into a 14-by-22-inch rectangle on a lightly floured surface.

Filling: Mix together brown sugar, raisins, and chocolate. Brush butter on dough, and sprinkle filling on top, leaving a 1-inch border.

Starting from a long side, roll up dough; cut crosswise into 12 slices. Place 6 slices flush against the side of a buttered 10-inch tube pan. Place remaining 6 slices, cut sides together, around tube of pan. Cover, and let rise until doubled, about 1 hour 30 minutes.

Preheat oven to 350 degrees. Bake cake until golden and a toothpick inserted into the center of cake comes out clean, about 40 minutes. Let cool in pan on a wire rack 15 minutes. Unmold, and let cool completely on rack, about 1 hour. Dust with confectioners’ sugar before serving.