Recipe from Cioccolato facile e veloce con il microonde by Denis Buosi Photography Francesca Moscheni   Preparation time: 30 minutes Resting time: 12 hours Cooking time: 2 minutes and 30 seconds Difficulty: medium  Yields 50/70 cookies 320 g unsalted butter 150 g powdered sugar 450 g flour 1 egg 40 g unsweetened cocoa powder Crystallized brown sugar for decorating Soften the butter in the microwave for approximately 30 seconds (microwave setting, 750 W). Sift the flour with the cocoa powder. Blend the butter and the sugar. Add the egg and continue beating then incorporate the flour and cocoa mixture. Beat until the batter is smooth and compact. Divide the batter into 4 or 5 equal parts rolling them with the palm of your hand to form small cylinders approximately 3 cm in diameter and 20 cm long. Transfer to a baking sheet lined with parchment, cover with cling film and refrigerate for 12 hours. Remove the dough from the refrigerator. Using a pastry brush slightly dampen each cylinder with a little water and then roll in the crystallized brown sugar.  Cut each cylinder crosswise forming discs approximately 2 cm thick. Arrange the discs on the microwave oven's crisp® tray and bake (Crisp® function) for  2 minutes and 30 seconds. Allow to cool prior to serving. The cookies may be stored for up to 60 says in a hermetically sealed container in a cool dry place in.