In a small bowl stir together the sugar, milk powder, and xanthan gum.

Pour the corn syrup and milk into a medium pot, whisking constantly, add the sugar mixture and stir until combined and smooth. Set over medium heat and cook without simmering just until the sugar is dissolved, about 3 minutes.

Remove the pot from the heat and whisk in the cream. Pour the mixture into an airtight container and refrigerate until well chilled. This is best done a day in advance. Store for up to a week in the fridge.