In a food processor, blitz the pistachios to a coarse, sandy texture. Alternatively, use a mortar and pestle.
Set aside 2 tablespoons (30 ml / 1 fl oz) of the ground pistachios for topping later.
In a large mixing bowl, combine the all-purpose flour, rice flour, all but 1 tablespoon (15 ml / 0.5 fl oz) of the sugar, salt, orange zest, chopped dates, cardamom, and the larger portion of the ground pistachios.
Add the diced cold butter.
Using your fingertips, rub the cold butter into the flour mixture until it resembles coarse breadcrumbs. Gently bring the mixture together with your hands to form a dough.
Knead briefly on a clean surface until smooth, but be careful not to overwork it.
Divide the dough in half.
Roll each half into a log approximately 2 inches in diameter.
Wrap each log tightly in plastic wrap and refrigerate for at least 45 minutes to 1 hour, until firm.
Preheat your oven to 325°F / 165°C.
Line two large baking sheets with parchment paper.
Remove one dough log from the fridge and unwrap it.
Using a sharp knife, slice the log into ¼-inch thick rounds.
Arrange the cookies on the prepared baking sheets, leaving about 1½ inches of space between them as they will spread.
Sprinkle the tops of the cookies with the remaining 1 tablespoon (15 ml / 0.5 fl oz) of sugar and the reserved 2 tablespoons (30 ml / 1 fl oz) of ground pistachios.
Bake for 20 to 25 minutes, or until the edges are a pale golden color. Avoid letting them brown.
Let the cookies cool on the baking sheet for 10 minutes before carefully transferring them to a wire rack to cool completely.
Don't skip the chilling time! A firm, cold dough is key to preventing the cookies from spreading too much in the oven and helps develop a richer flavor.
