In the bowl of a stand mixer fitted with the paddle attachment or in the mixing bowl, beat the coconut sugar and coconut oil on medium speed until fluffy. Add the flax egg and vanilla and mix until nicely blended. If you prefer, you can stir the ingredients in the mixing bowl with a sturdy spoon.
Add the almond flour, cardamom, baking soda, and salt to the wet ingredients and, with the mixer on medium-low, mix until well incorporated, or mix the ingredients by hand. Fold in chopped chocolate and pistachios.
Cover the bowl with plastic wrap and refrigerate for at least 1 hour, or up to 24 hours. This chilling time lets the flavors meld and the cardamom flavor permeate the dough.
Preheat the oven to 350°F. Line a baking sheet with parchment paper.
Use a medium cookie scoop that holds about 1 1/2 ounces of dough to form cookies. You can also use a spoon to form rounded mounds of dough. Put them about 2 inches apart on the prepared baking sheet. If desired, press more chocolate chunks, pistachios or both onto the top of the cookies (I do this to make them look pretty!). Bake for 10 to 12 minutes, until the cookies are just beginning to turn golden brown around the edges.
Let the cookies cool for 10 minutes on the baking sheet and then move them to a wire rack to cool completely. Store the cookies in an airtight container on the counter for 3 days, or in the refrigerator for up to 1 week.