Ingredients

CHOCOLATE DOUGH:1 cup butter, softened1-1/2 cups sugar2 large eggs, room temperature2 teaspoons vanilla extract2 cups all-purpose flour2/3 cup baking cocoa3/4 teaspoon baking soda1/2 teaspoon salt1 cup coarsely chopped pecans5 ounces white baking chocolate, choppedVANILLA DOUGH:1 cup butter, softened1-1/2 cups sugar2 large eggs, room temperature2 teaspoons vanilla extract2-3/4 cups all-purpose flour2 teaspoons cream of tartar1 teaspoon baking soda1/2 teaspoon salt1 cup coarsely chopped pecans4 ounces German sweet chocolate, chopped

Preparation

For chocolate dough, in a large bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Beat in eggs and vanilla. Combine the flour, cocoa, baking soda and salt; gradually add to creamed mixture and mix well. Stir in pecans and white chocolate.

For vanilla dough, in another large bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Beat in eggs and vanilla. Combine the flour, cream of tartar, baking soda and salt; gradually add to creamed mixture and mix well. Stir in pecans and German chocolate. Cover and refrigerate both doughs for 2 hours.

Divide both doughs in half. Shape each portion into a 12-in. roll; cover. Refrigerate until firm, about 3 hours.

Preheat oven to 350°. Uncover and cut each roll in half lengthwise. Place a chocolate half and vanilla half together, pressing to form a log; repeat with remaining dough. Cover and refrigerate until the dough holds together when cut, about 1 hour.

Using a serrated knife, cut into 1/4-in. slices. Place 2 in. apart on greased baking sheets. Bake until set, 8-10 minutes. Remove to wire racks to cool.