Line a baking sheet with parchment paper.
In a large bowl, add the butter and cream cheese and use an electric mixer to beat until it becomes light and fluffy, scraping down the sides as needed to ensure even mixing.
Scrape down the sides one more time, then add the flours, milk, and salt and use the electric mixer to combine (it will just form clumps). Then use your hands to finish combining until no flour remains. The best way to do this is to use a kneading motion. If it's too dry, add another teaspoon of milk. If it’s too wet, add some flour. You want a playdough-like consistency.
Divide the dough in half, shape each half into a smooth ball, then flatten into a 1-inch thick disc. Wrap in plastic wrap (or put in a ziptop bag) and place in the fridge for 30 minutes to chill.
Preheat the oven to 375F. In a small bowl, mix together the pistachios and cardamom.
Lightly flour a clean counter. Place the dough on top of the flour and use a rolling pin to roll out into about an ⅛-inch thick disc. You want the dough to be thin - if it’s too thick, the ratio of dough to jam will be off and they will taste too dry. Use a bench scraper or knife to trim the rough/ragged edges off (set the scraps aside to roll out later).
Dollop ¼ cup jam in the center of the dough and spread it out gently using the back of a spoon, leaving about ¼-½-inch of space along the edges (add more jam if it looks like you need more). Sprinkle about half of the pistachio/cardamom mixture all over.
Use a bench scraper or knife to cut the dough into quarters then cut those quarters into four triangles (like a pizza). Starting at the wider end, gently roll the triangles up, then place them on the baking sheet, making sure that the tip is underneath so that they don’t unravel.
Bake for 10-15 minutes or until the bottoms are a dark golden brown and tops are starting to turn golden. Transfer the cookies to a cooling rack to cool off for at least 20 minutes.
Repeat these steps with the other disc while the first batch is in the oven. Lastly, combine all the dough scraps into a ball, roll them out, and make mini rugelach - chefs treat!
I think the cookies are beautiful as is, but you could also dust them with some powdered sugar.