Preheat your oven to 375°F. Pour the melted butter directly into a 9x9 inch or 2-quart baking dish. Do not stir it; the butter acts as a non-stick barrier and fries the bottom of the batter.
In a small bowl, toss the drained peaches with the cinnamon, vanilla, bourbon, and reserved syrup. Letting the peaches sit for 5 minutes allows the spices to penetrate the fruit.
In a separate bowl, whisk together the flour, granulated sugar, baking powder, and nutmeg. Gradually whisk in the milk until just combined. A few small lumps are fine; over-mixing will result in a tough cobbler.
Pour the batter directly over the melted butter in the baking dish. Do not stir.
Gently spoon the spiced peaches and any remaining juice over the batter. As the cobbler bakes, the batter will rise up and around the fruit, creating a "cobbled" appearance.
Sprinkle the Turbinado sugar evenly over the top. This creates a thin, crackly crust that sets this version apart from the traditional soft-topped style.
Bake for 40–45 minutes until the top is a deep golden brown and a toothpick inserted into the cake portion comes out clean.