Muddle the black cardamom in a mixing glass, before adding the remaining ingredients and ice. Shake hard for a few seconds, then strain over ice into an old-fashioned glass. Garnish optional.
To make the syrup, add molasses to boiling water at a ratio of 2:1. Stir until dissolved, allow to cool and bottle.
For the cold tea, steep 1 tbsp chai tea leaves to about 150ml boiling water for 3 minutes. Leave to cool.