Whisk the caster sugar and xanthan gum together in a medium pot. Combining them helps disperse the xanthan gum which means less clumps in your ice cream.
Have a silicone spatula in hand as you weigh in the milk. Quickly stir the mixture and scrape the sides of the pot to ensure no sugary xanthan mixture lurks in the corners.
Add the remaining ingredients and stir to combine. Transfer to the stove for cook for 1-3 minutes or until the liquid sugar has totally dissolved and the mixture is smooth.
Allow to come to a hand comfortable temperature before pouring into the 470ml Ninja Swirl tub. Make sure the bottom swirl mechanism is closed before you add mixture.
Freeze for 24 hours with the lid off. Leaving the lid off can help prevent the mixture forming a hump which can damage your machine.
When ready to eat, process your ice cream using the scoop and ice cream function. Scoop function doesn't over-process high fat mixtures and split them like the soft serve function does.
If the mixture appears soft, place it in the freezer for 10-30 minutes. The higher the sugar content, the softer the mixture will be.
Swap lids and put the piping nozzle onto the machine. Open the bottom mechanism and process the mixture using the soft serve lever. If you get an error message, allow the mixture to soften for 5-10 minutes before continuing.
There will be some mixture leftover in the machine that is a bit icy. You can eat it as is or try re-spinning it for a scoop. This is the same for every Swirl - there is a bit left in the bottom that the machine doesn't seem to process.