Prepare a medium-sized cast-iron skillet with baking spray.
For the filling
Cut each peach into 6 slices and place in a large mixing bowl. Drizzle the bourbon and the maple syrup over the peaches, stir and let soak as you prepare the dry ingredients.
In a separate bowl, combine the brown sugar, flour, cinnamon and vanilla bean seeds scraped from 1/2 of the pod. Crush the seeds into the rest of the ingredients to release maximum vanilla flavor.
Pour the dry mixture over peaches and toss to evenly coat. Lay the peaches flat in the prepared skillet beginning on the perimeter and working your way in. Should result in 2-3 layers.
For the topping
Melt the butter in a small saucepan and scrape in the seeds of 1/2 vanilla bean. Add the scraped pod to the butter and simmer for 3-5 minutes to infuse. Set aside to cool and discard the pod.
In a mixing bowl, combine the oats, crushed pecans, brown sugar, flour and salt. Pour the room temperature butter over the mixture and stir to combine. You may decide to use your hands to press the ingredients together into small clumps.
Sprinkle the topping over the peaches in an even layer and bake for 45 minutes, or until the topping is crisped and browned and the filling is bubbling.