In a medium saucepan, combine 2 cups water, 1/2 cup granulated sugar, the seeds and pod of the vanilla bean, and the cinnamon stick. Bring to a simmer over medium heat, stirring until the sugar dissolves.

Add 1/2 cup bourbon and 2 tablespoons lemon juice, stirring to combine.

Nestle the 4 peeled, halved, and cored pears in the liquid. Cover and reduce heat to low. Simmer for 15–20 minutes, gently turning pears halfway through so they cook evenly.

Carefully transfer the pears to a plate with a slotted spoon, then increase heat to medium-high. Continue simmering the poaching liquid until it’s reduced by half, about 10 minutes.

Discard the vanilla pod and cinnamon stick. Return the pears to the pan or spoon the syrup over them before serving.