These cookies have been on my to-try list for an awfully long time. Today, my friend Nitasha stepped up to help me take on the challenge, and we knocked out quite a few (this image shows them about true to size). All in all, I think the project took us about five hours (several chilling sessions are needed), but we managed to busy ourselves with other creative projects in the downtime. For fun, I threw in some orange zest with the chocolate portion of the cookie, which is very subtle in the small cookie. But if you divide the dough with a little extra on the chocolate side (as we did), you have room for a few extra chocolate-only cookies. I guess that cheese-over-chocolate diet isn't happening yet.
CHECKERBOARD COOKIES
1 lb unsalted butter, room temp.
1 cup sugar
2 large eggs, 1 egg white (very important)
2 tsp vanilla extract
5 cups flour
3 tbsp Dutch-process cocoa
Mix the butter on medium until light and fluffy. Add sugar gradually and continue to beat until it becomes pale and fluffy. Add each whole egg, one at a time, and blend in vanilla. Combine flour and salt separately, and gradually stir into the butter mixture. Halve dough and set one half in a covered bowl in the refrigerator. Mix the cocoa into the remaining half on low speed, until fully incorporated and no marbled spots are left. Now, take each separate set of dough, shape into rectangular loaves, and cover with plastic wrap. Refrigerate for at least 1/2 hour until firm.
Roll out each of the doughs separately but quickly (to avoid the dough softening too much) until they are approximately 1/2 cm thick. (You can leave it at 1 cm for a larger overall cookie). Brush one color of dough with the left over egg white and place the other color on top (even out sides with pastry knife). Cut in half, brush one half with egg, and place the other half of the chocolate-vanilla layers again, so you have vanilla, chocolate, vanilla, chocolate in tiers either up or down. Finally, cut lengths one more time to the same width as the layers are high. Wrap and refrigerate again at any point where the dough is getting too soft to cut cleanly. Dough can be frozen, if you save some dough for later.
At this point, you should have chilled, rectangular logs whose length is greater than the other two equal dimensions. Pre-heat the oven to 350 degrees, and line baking pans with parchment paper. With a sharp knife, cut half-centemeter high cookies from the checkerboard log crosswise. Place the cookies on baking pans, 1 inch apart, until firm, 12-15 minutes. Rotate pans once while baking if oven heat is not even. Cool completely.
