Use a peeler to remove the zest in wide strips from ½ of the orange
Place the cranberry juice into a measuring cup and squeeze in the orange juice to make 1 ½ cups liquid
Place the cranberries, cranberry/orange juice, orange zest, sugar, and salt (along with the coriander powder if using) in a small/medium pan and set over medium heat
Bring to a simmer and allow to cook (stirring occasionally) until the cranberries burst and the mixture begins to thicken (apx 20 minutes)
Remove from heat - Remove and discard the orange zest - Add the vanilla extract (if using)
Use an immersion blender (or transfer to a blender as alternative) to purée until smooth
Pour purée through a fine mesh sieve into a serving dish or mold (use a rubber/silicone spatula to push the mixture through and discard any solids)
Place in the refrigerator and allow to chill until it sets (apx 3 hours) - Serve chilled