In a small bowl, whisk together the olive oil, vanilla, cinnamon, bourbon, and maple syrup until combined.
In a medium bowl, combine nuts and olive oil mixture; stir thoroughly to coat the nuts. Spread onto a large, rimmed baking sheet, then evenly sprinkle the flake salt over the top. Bake for 10 minutes; move the nuts around on the baking sheet.
Remove nuts from oven, then evenly sprinkle the rosemary over the top and return to the oven for 5-10 more minutes—the rosemary will become fragrant.
Remove from the oven and allow to cool completely before serving.