Preheat oven to 160ºC (325ºF). Place the butter, brown sugar, cinnamon and mixed spice in a food processor and process until smooth. Add the flour, whole egg, egg yolk and water and process again to form a smooth dough. Knead lightly, wrap in plastic wrap and place in the fridge for 30 minutes to chill.
Roll out the dough between sheets of non-stick baking paper to 5mm thick. Using Christmas cookie cutters, cut out shapes. Make small holes in the top of each cookie for string to be looped through. Place on baking trays lined with non-stick baking paper. Bake for 20 minutes or until golden. Cool on wire racks.
Brush cookies with the eggwhite and press the brushed side into the sugar to coat. Place on baking trays and return to the oven for 10 minutes to set the sugar. Cool on wire racks. Makes 45.