In a large pot, combine sugar, cinnamon, vanilla bean, cloves, allspice, and cardamom. Place over high heat.
Once the sugar begins to melt and caramelize slightly in places, stir occasionally to ensure somewhat even caramelization and some toasting of spices.
Once sugar is all melted and caramel is almost the color of maple syrup, remove from heat and carefully add cider, then vinegar, ginger, apple and citrus peels.
Return pot to heat, bringing to a gentle simmer over medium heat.
Stir occasionally. Once all sugar has melted back down, remove from heat and allow to cool to room temperature before pressing through a fine mesh strainer.
Keep chilled, shaking gently before using as shrubs tend to separate a little in storage.
Keeps for at least a month.