1 In a small pot, heat the milk, saffron, and 1 teaspoon of sugar together until the milk is steamy. Remove from heat and stir to dissolve the sugar. Let cool until about 115°F, or warm to the touch, but not hot.
2 Sprinkle the yeast over the warm saffron-infused milk and let sit for 5 to 10 minutes until foamy.
3 In the bowl of a stand-up mixer* whisk together 3 1/2cups of the flour, remaining 1/4 cup of sugar, salt and ground cardamom if using.
4 Make a well in the center of the flour and add the yeast milk saffron mixture, the eggs, the butter, and the sour cream. Mix the ingredients until well incorporated.
5 Switch to the dough hook of your mixer (if using, otherwise knead by hand). On low speed start to knead the dough. Slowly add additional flour, a tablespoon at a time, kneading to incorporate after each addition. Do this until the dough is still a little sticky to the touch, but does not completely stick to your hands when you handle it.
6 Shape the dough into a ball and place in a large bowl. Cover with plastic wrap. (Note at this point you can make ahead and refrigerate overnight if you wish.) Let sit in a warm place for 1 to 2 hours, until the dough has doubled in size. (One way to tell that the dough is ready is that you poke your finger in it and it takes quite a bit of time for the indentation left by your finger to go away.)
7 When the dough has doubled in size, gently press it down and knead it a couple of times. Break off a piece and form it into a ball about 2 inches wide (65 grams if you are weighing). Roll the ball out into a snake, about 14 inches long. Then Curl the ends in opposite directions, forming an “S” with spirals at each end. Place on a lined baking sheet and repeat with the rest of the dough. Cover with plastic wrap and place in a warm spot until the dough shapes double in size, 30 minutes to an hour.
8 Preheat oven to 400°F. Using a pastry brush, brush some beaten egg over the tops and sides of the uncooked buns. Place raisins in the centers of the “S” spirals. Place in the oven and cook for about 10 to 11 minutes (turning halfway through cooking to ensure even browning), until the buns are golden brown. Remove from oven and let cool for 5 minutes before eating.