Zest the orange straight into a pan.

Juice the orange and add enough water to make 1 cup of liquid.

Put the orange juice water, cranberries, and xylitol in the pan with the zest and stir well. Over a high heat, bring to a boil. Be extremely careful as this will reach very high temperatures.

Reduce the heat to a simmer and cook for 15 minutes, stirring well and often.

Remove from the heat and carefully pour the sauce into a bowl. Let cool completely.