Gently warm the milk and ensure the gelatin dissolves, around 3-4min - test by putting a spoon in and seeing if you can see any lumps, there should be none.
Remove from the heat and add the remaining ingredients and whisk to combine. The cinnamon may seem to float on the top - don't worry just try to combine as best you can.
Pour into the ramekins/custard dishes and chill for at least 2hrs, 4+ or overnight if you want to remove from dishes.
To remove from the dish, if you want to, sit the dish in a bowl of hot water for a minute then ease the top edge away with a knife before inverting on a plate (if the plate is damp, you can slide it to reposition if you need to).