Ingredients
3/4 cup butter, softened3/4 cup sugar1 large egg yolk, room temperature1/2 teaspoon vanilla extract1-3/4 cups all-purpose flour1-1/2 teaspoons baking powder1/2 teaspoon salt1 ounce semisweet chocolate, melted3 tablespoons 2% milk, warmed
Preparation
Cream butter and sugar until light and fluffy, 5-7 minutes. Beat in egg yolk and vanilla. In another bowl, whisk flour, baking powder and salt; gradually beat into creamed mixture. Divide dough in half. Add melted chocolate to 1 portion; mix well. Cover and refrigerate both portions until chilled.
Divide each portion of dough into fourths; shape each into a 5-in. log. Flatten into triangular-shaped logs. Brush long sides with milk. Assemble 1 large roll by alternating 2 chocolate and 2 plain logs. Repeat. Wrap and refrigerate until firm, about 4 hours.
Preheat oven to 375°. Unwrap each roll; cut into 1/4-in. slices. Place 2 in. apart on lightly greased baking sheets. Bake until set, 8-10 minutes. Remove from pans to wire racks.
