In a small saucepan, mix the three ingredients together. Turn on the heat on low, and stir until the mixture has lost its 'grittiness' (usually just a few minutes). Don't let it start to bubble or boil, as it'll turn the mixture from transparent to solid when poured into the mould.

Turn the heat off and let it sit for a minute or two. It won't start to harden straight away, so it's best to let some heat off of the mixture.

Get your mould ready (FYI: you don't need to spray the mould, it pops out easily) and clear a space in your freezer.

Pour the mixture into the mould, move quick and pop into the freezer.

Check in about 2-3 minutes, it should be mostly hardened. If not quite there, check every minute until it's firm. You also won't want to let it sit in the freezer, as it'll make the gummy mixture go weird.

Pull out of the freezer and undo from mould.