Combine granulated sugar, brown sugar, orange juice, water, cinnamon stick, and salt in a saucepan over medium-high heat and bring to a boil, stirring until the sugar dissolves. Visual cue: the liquid should look fully clear and glossy before adding cranberries.

Add fresh cranberries and return to a boil over medium-high heat. Visual cue: the berries will rapidly start popping and the liquid will bubble all over.

Reduce heat to low and simmer for 10-12 minutes, stirring often, until most berries burst and the sauce thickens. Visual cue: you should see split berries and a thicker, spoon-coating consistency.

Remove from heat and stir in orange zest and vanilla extract, then discard the cinnamon stick. Visual cue: the sauce will look darker and more fragrant right after adding the zest.

Cool to room temperature, then chill so it thickens further as it cools. Visual cue: the surface will become more set and jelly-like once refrigerated.