Heat oven to 350°F. Line a 9" square baking pan with parchment paper so the paper goes over the sides of the pan.

Use a food processor to chop the pistachios until the are very finely ground, but not pasty. Add the flour, salt, baking powder, and cardamom and pulse to combine.

In a large bowl, whisk together the melted butter for the blondies and the brown sugar until smooth and shiny - it will take a minute, the butter will separate at first. 

Whisk in the eggs until incorporated. Add the pistachio mixture and mix until combined. 

Stir in the white chocolate chips until they are well distributed and pout the batter into the prepared pan. Spread the batter into an even layer. 

Bake until the sides are brown and starting to pull away from the pan, about 25-27 minutes. The middle will be slightly paler. 

Place the entire pan on a cooling rack and cool completely.

While the blondies cool, make the frosting. 

Using a mortar and pestle if you have one, or a microwave-safe bowl and the back of a spoon, grind the saffron until it is finely ground. 

If needed, transfer to a microwave-safe bowl and stir in the milk. 

Mircrowave on high until mixture is frothy around the edges but not boiling, about 30 seconds. 

Place in the refrigerator or freezer to cool quickly.

In a large bowl with an electric or stand mixer, if you have one, beat the cream cheese and butter until smooth. This can be done by hand if needed.

Add confectioners' sugar and salt, beat until no clumbs of sugar remain and mixture is smooth. 

Add the cooled saffron milk and mix until well combined. 

Once the blondies have cooled completely, use a spatula to apply the frosting to the top and spread it evenly. 

Crush or chop some pistachios and sprinkle on top of the frosting.

Refrigerate for at least 2 hours before eating.