In a large bowl, combine the flour, vanilla, icing and diced butter.

Rapidly mix the ingredients with your hands and knead well. If the dough is sticky, sprinkle some flour and knead one more time to form a smooth dough.

Divide the dough into two halves.

Add the cocoa powder to one of the pastry halves. Knead well until the cocoa is well diffused with the dough.

Roll out each dough between two sheets of lightly floured parchment papers to a 1 1/4 cm, about ½ inch-thick and to a rectangle 30 x 35 cm /12 x 14 inches.

Carefully turn out the vanilla dough onto the chocolate dough.

Use the parchment paper as aid to roll the two rolls together tightly. Cover with plastic wrap and refrigerate for at least one hour, this will facilitate the cutting process later.

Preheat the oven to 180°C/350°F.

Line two baking sheets with parchment paper.

Cut the rolls into ½ cm / 1/4 inch thick.

Place the pinwheel cookies on the baking sheets, and bake for 12-15 minutes, or until slightly golden. Enjoy!