This recipe for German black and white Christmas cookies (known as Schwarz-Weiß-Gebäck in German) takes a fun looking but often rather bland cookie and gives it a taste that matches its looks. We also share our tips for easy checkerboards and swirls.
Mix flour, sugar, baking powder, and salt in a mixing bowl. Add the butter and rub in with your fingertips until the mixture resembles fine breadcrumbs. Add the egg yolks and vanilla essence and mix until well combined and it again resembles fine breadcrumbs. Quickly squeeze the crumbs together to form a large ball.
Cut the dough ball in half. Add the white chocolate to one half and knead until well combined. Add the dark chocolate and cocoa powder to the other half and knead that until well combined too.
Roll each lot of dough out on a lightly floured work surface until they are 1 cm thick. Cut each lot of dough into a large square then into strips about 1 cm wide. Paint each side that will touch the other layer with egg white to help them stick. Layer the strips on top of each other black then white or white then black. Paint one long side with egg white then place two layered strips next to each other lengthwise so that they form a chessboard pattern when you look from the end. Press the two strips together gently then wrap the joined strips in plastic and refrigerate for two hours.
Two hours later: Preheat the oven to 160°c. Line two trays with baking paper.
Slice the checkered strips into slices (checkered squares) approximately 5 mm thick and place on the trays, leaving a little room between each biscuit.
Bake on the middle rack for 10 to 12 minutes or until they have just started to go brown. Remove from the oven and allow to cool for a few minutes before transferring them to a wire rack to cool completely.
Notes
You can of course make other patterns with your dough. For spirals, for example, roll out the dough, paint each layer with egg white then layer one 'white' layer over a 'black' layer (egg white sides touching). Starting at one side, roll the dough inwards to create a long snail. Cover and refrigerate.