Preheat oven to 400 degrees Fahrenheit.
Combine 1 tablespoon sugar, warm water, and yeast in a bowl. Wait for yeast to bubble and foam.
In a saucepan combine butter, milk, and saffron.
Heat until warm and butter is melted, do not boil.
Let cool off for 8 minutes.
Add milk mixture to yeast in the bowl.
Add flour and 1/2 cup sugar and beat until dough is smooth.
Lay out dough on a lightly floured surface and knead for 1 minute. Transfer dough to a lightly oiled bowl, cover loosely, and let rise in a warm place for 1 hour.
Divide dough into 16 pieces.
Roll each piece into 1-inch-wide, 6-inch-long strips.
Coil ends in opposite directions, forming a tightly curled inversed S-shape.
Place on a baking sheet and let rise for another hour.
Brush buns with beaten egg yolk and place 1 raisin in the center of each curl, 2 per bun.
Bake 10-15 minutes until golden brown.