Preheat the oven to 375 degrees F.
In a large heavy pot, combine the potatoes, sugar, water, orange juice, vanilla beans, orange zest, cinnamon, and salt. Bring to a simmer over high heat. Lower the heat, cover and simmer, stirring occasionally, until the potatoes are tender, about 20 minutes. Strain the potatoes out of the sauce and place in a casserole dish. Return the sauce to the pan.
Add the bourbon to the sauce and continue to cook until syrup is thickened, about another 15 minutes. Pour the syrup over the potatoes and place in the oven. Bake until the potatoes are browned, about 10-15 minutes. Remove from the heat and add the butter, stirring gently to incorporate. Serve immediately.