Half a batch of vanilla dough has cocoa powder added; the way the doughs are shaped and cut showcases the two distinct flavors with two designs. Kids particularly enjoy making—and eating—these cookies.

　　

Ingredients

Makes 34 bulls¿s eyes and 28 spirals

　　1 1/2 cups (3 sticks) unsalted butter, room temperature

　　1 3/4 cups sugar

　　2 eggs plus 1 large egg white, lightly beaten

　　1 teaspoon coarse salt

　　2/3 cup whole milk

　　1 tablespoon pure vanilla extract

　　5 cups all-purpose flour, plus more for work surface

　　1/4 cup unsweetened cocoa powder (not Dutch-process)

　　

Step 1

Make dough: Put butter and sugar in the bowl of an electric mixer fitted with the paddle attachment; mix on medium speed until creamy. Add whole eggs and the salt, and mix until combined. Mix in milk and vanilla. Reduce speed to medium-low. Add flour a little at a time, and mix until just combined.

　　

Step 2

Remove half of the dough from mixer; set aside. Add cocoa powder to remaining dough. Mix on low speed until combined.

　　

Step 3

Form bull’s-eyes: Roll out one-quarter of the chocolate dough on a lightly floured surface to a 12-inch rod about 3/4 inch thick. Transfer to a baking sheet; refrigerate until firm, about 20 minutes.

　　

Step 4

Roll out half of vanilla dough on lightly floured parchment to a 12 by 4-inch rectangle about 1/2 inch thick. (It should be as long as the chocolate rod and just wide enough to wrap around the rod.) Transfer to a baking sheet, and refrigerate until firm, about 20 minutes. Brush top of vanilla dough with egg white, then place chocolate rod along length of vanilla dough. Roll vanilla dough with your hands to enclose the chocolate rod. Trim excess. Gently pinch dough to seal. Refrigerate until firm, about 20 minutes.

　　

Step 5

Form spirals: Roll out remaining chocolate dough on a lightly floured piece of parchment paper to 1/4 inch thick. Roll out remaining vanilla dough on a lightly floured piece of parchment paper to 1/2 inch thick. Trim doughs to two 9 by 6-inch rectangles. Refrigerate until firm, about 20 minutes.

　　

Step 6

Brush egg white onto top of each rectangle, then place vanilla dough on top of chocolate dough. Starting at one long side, roll up dough. Gently pinch and press the edge of the roll to seal it. Refrigerate until firm, about 20 minutes.

　　

Step 7

Bake cookies: Preheat oven to 350°F. Cut logs crosswise into 1/4-inch-thick rounds. Space 1 inch apart on baking sheets lined with parchment paper. Bake until firm but not browned, 12 to 15 minutes, rotating sheets halfway through. Let cool on sheets 3 minutes, then transfer to wire racks to cool completely. Cookies can be stored in airtight containers at room temperature up to 3 days.

　　Martha Stewart's Cookies