In a saucepan, melt 2 tablespoons of butter over low heat. Add the brown sugar & stir until it dissolves, about 3 minutes. It will become a wet looking mass of sugar that slides around the pan. Stir in the cinnamon, cardamom & salt. Add the orange juice, be careful it will sizzle up & splatter a little bit. Cook about one minute until it thickens slightly.