In a small saucepan, scald milk until just before boiling.
Take off heat and add butter, sugar, and salt. Stir to melt and let cool to lukewarm.
Sprinkle yeast in warm water and mix to dissolve. Let soften and foam for about 5 minutes.
Pour cooled milk mixture into a large bowl, add yeast, egg, and cardamom. Gradually stir in 3 ¼ c. flour.
Knead in remaining flour until dough is soft and not sticky.
Put dough in a greased bowl, cover, and let rise in a warm place for 1 ½-2 hours.
For filling, beat butter until soft, then add sugar and cinnamon.
Preheat oven to 350° and grease a muffin tin.
Roll out dough into a rectangle and spread filling over it.
Fold dough in thirds, slice into strips, braid, and form knots.
Let knots rise for 30-45 minutes.
Bake for 20 minutes or until lightly browned. Dust with icing sugar before serving.
