Technically, this is possible to do. However, after strenuous research trying to find the definitive answer as to how many pods would be needed to replicate the same depth of flavour created when using ground spice, the results were highly inconclusive. So, I tested the syrup with what I thought would be the ideal number of pods. But my trusty taste testers quickly returned the verdict that the version made using ground cardamom was superior. If you only have cardamom pods, I'd go with at least 6-8. And don't forget to split them open before adding to the pan.