Add the ground almonds, icing sugar (or powdered Erythritol or Xylitol), cinnamon, and cardamom to a food processor and blend for a couple of seconds. If you don't have a food processor, simply add the ingredients to a medium-sized bowl and stir with a spoon.
Now add the orange juice and orange zest and mix again until the dough is crumbly and sticks together when you press it between your fingers. If it's too dry, add a little more orange juice.
Remove the dough from the food processor and shape it into a ball. Wrap it in cling foil and chill in the fridge for about 30-60 minutes.
Place the chilled dough between 2 layers of plastic wrap (or parchment paper) and roll it out with a rolling pin. It should be about 0.5-0.7 cm thick (1/4 inch).
Preheat the oven to 350 degrees Fahrenheit (175 degrees Celsius) and line a baking sheet with parchment paper.
Use a star-shaped cookie cutter to cut out the cookies. You can dip your cutter in a bowl of powdered sugar between cutting the cookies. This will help prevent the dough from sticking to the cutter.
Depending on the size of your cookie cutter the recipe will make 30-40 cookies. Transfer them to the prepared baking sheet and bake in the oven for 8 minutes. Depending on the thickness of your cookies, the baking time may vary by 1-2 minutes. Let them cool completely.
Meanwhile, make the glaze by mixing icing sugar (or powdered Xylitol) and water in a small bowl until it's a creamy paste. If it's too thick add a little more water and if it's too thin add more icing sugar.
Brush the glaze on the cooled cookies and let it dry. Enjoy! Store cookies in a cookie tin in a cool place for up to 2-3 weeks.