Instructions: Preheat the oven to 325 degrees F. Line a cookie sheet with baking parchment.

Make the vanilla shortbread: In a large bowl, whisk together the flour, sugar, and salt. With a pastry cutter, cut the butter into the dry ingredients until it is evenly distributed and the size of small crumbs.

Stir in the vanilla and mix the dough, shaping it with your hands until it comes together to form a ball. Transfer the dough to a lightly floured work surface and roll it out until 1/4 inch thick. Cover with plastic wrap and set aside.

Make the chocolate shortbread: In a ceramic or glass bowl covered with plastic wrap, heat the chocolate in a microwave oven on High for 30-second intervals, stirring after each interval, until smooth. Let cool to lukewarm. In a bowl, whisk together the flour, sugar, cocoa, and salt. Put the butter in a bowl and whip until light and fluffy using the electric mixer on medium speed. Add the melted chocolate and beat until smooth. Beat in the vanilla and instant coffee, if using. Add the dry ingredients and combine until a dough forms. Gather the dough into a disk and flatten it slightly. On a lightly floured surface, roll it out until 1/4 inch thick.

(Should the dough be too soft to roll, wrap it in plastic wrap and chill until firm.)

Place the chocolate dough on top of the plain shortbread dough and with your hands gently but firmly roll the doughs into a log. Wrap the log in plastic wrap and chill for about 1 hour, or until firm. With a sharp knife, cut the chilled dough into slices about 1/2 inch thick and arrange them on the prepared cookie sheet, leaving 1 inch between. Bake the cookies for about 20 minutes, or until golden around the edges. Remove the cookies with a spatula to wire racks to cool. Store in any sealed container, such as a tin or jar. The cookies can also be frozen, wrapped first in plastic wrap and then in aluminum foil.

Make 2 dozen cookies

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