First, add the water, sugar, bourbon, orange juice, cinnamon sticks, and vanilla bean paste to a large pot or dutch oven. Stir together and bring to a simmer.
Once simmering, peel the pears and use a melon baller or spoon to "core" them from the bottom and remove the seeds. Then, immediately add the peeled and cored pears to the simmering syrup. It's very important to ONLY peel the pears once the liquid is simmering or you risk the pears browning.
As soon as the pears are in the pot stir them so they are completely coated with liquid, Then, turn the heat to a very low simmer and cook the pears in the syrup for 20-25 minutes (or up to 40 minutes for large pears).
Since the pears will not be fully immersed in the syrup, make sure to rotate the pears every 5 minutes so they poach evenly on all sides. You can also stand them up in the syrup if needed to give the bottoms extra cooking time.
Once the pears are poached, gently remove them from the pot and transfer to a bowl to allow to cool. You will know the pears are poached when they are slightly transcluent on the outside and easy to pierce with a fork or knife, yet not and mushy (which would mean they are overcooked). You will also want to remove and dicard the cinnamon sticks at this point.
While the pears are cooling, continue to stir & cook the remaining syrup at a low simmer to thicken for another 15 minutes. It should not brown or caramelize, but should become a sweeter thicker syrup during this additional cooking time.
To serve pears warm, add them to a plate and top them with the warmed syrup. If serving cold, store the pears and with the room temperature syrup in a closed container in the fridge until cooled. Then, serve with your choice of toppings & enjoy!