Preheat the oven to 300 degrees F (150 degrees C).
In a medium bowl, stir together the butter and sugar until smooth. Stir in flour and cardamom until well blended. Pinch off tablespoonfuls of dough, and roll into a thin rope. Join the ends together in a circle, and place on a greased cookie sheet. Place almond halves on the joints where the circles come together.
Bake for 20 minutes in the preheated oven. The cookies should remain white, but may turn golden at the very edge.