1¼ cups (125 grams) walnut pieces, roasted until lightly golden
1 cup icing sugar
2 tablespoons plain gluten-free flour or regular flour
¾ teaspoon ground mixed spice
2 teaspoons finely grated orange zest
3 tablespoons finely chopped crystallized ginger
1 x #6 egg (medium), lightly beaten
1 cup icing sugar
½ cup cream
100 grams dark chocolate
Rub any loose skins off the walnuts and place in a food processor along with all the remaining ingredients except the egg.
Process until finely chopped but not smooth. Add the egg and pulse to form a soft, sticky dough. It should look like chunky peanut butter. Scrape into a bowl, cover and refrigerate for 1 hour or until firm.
Preheat the oven to 170˚C (fan bake).
Liberally sprinkle the bench and your hands with icing sugar. Scoop out small teaspoons of dough and roll into marble-sized balls. They will triple in size when cooked.
Flatten the tops lightly with a fork then dip the tops into extra icing sugar to give a good coating. Place on lined baking trays about 3 cm apart. Chill one tray of cookies while the first tray is in the oven.
Bake for 8 minutes until golden and the tops have a crackled effect. Cool on the tray for 2 minutes then transfer to a cooling rack.
Ganache: Put the cream in a small saucepan and bring to just below boiling point. Take off the heat, add the chocolate and stir until smooth. Tip into a bowl and cool to a thick spreadable consistency.
Spoon the ganache into a piping bag and pipe a layer onto the smooth side of half of the cookies. Sandwich with the remaining cookies and dust with icing sugar if desired. Makes about 20 doubles depending on their size.
Unfilled cookies will keep for 3 days in an airtight container. Filled cookies will soften after 1 day.