Two-tone Swirl Cookies

For the plain dough: beat the butter and sugar in a mixing bowl until light and fluffy. Add the egg yolk and vanilla, and beat well until incorporated.

Sift in the flour, and salt and mix to a dough.

Shape into a log, wrap tightly in cling film and chill for 30 minutes.

For the chocolate dough: repeat the process, sifting in the cocoa and coffee with the flour. Shape and chill as for the plain dough

Using a sheet of non-stick baking paper for each log, gently roll out the chocolate and plain logs, side by side, to keep them the same size and shape into rectangles, about 4mm|1/4" thick.

Holding the paper lift the plain dough and place on top of the chocolate dough and trim the ends.

Lay the paper on top of the plain dough and using a rolling pin, lightly roll the two into each other so they stick together.

Take the long side of the rectangle closest to you and roll it tightly upwards, folding it down into itself, to form the core of the spiral. Press to seal and close any gaps.

Lift the paper up and around the spiral core so it is tight. Slowly pull the paper away from you, bringing with it the doughs.

Roll over so that the seam is facing up. Press the seam gently into the log, then place seam-side down onto a fresh sheet of non-stick baking paper. Roll tightly in this and chill for at least 2 hours until firm.

Heat the oven to 180°C (160° fan) 350°F gas 4. Line 2 baking trays with non-stick baking paper.

Cut the log into rounds and place on the baking trays, at least2.5cm|1" apart..