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 cook (stirring often) on medium-high heat until syrup is thickened, about another 15-30 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.