Start by peeling and slicing the fresh peaches. You should have about 6 cups of sliced peaches. Place them in a large bowl and sprinkle with 1/2 cup of granulated sugar and the ground cinnamon. Toss gently to coat the peaches evenly. Let them sit for about 15 minutes to release their juices.

Preheat your oven to 375°F (190°C). This ensures that your cobbler will bake evenly and develop a beautiful golden crust.

Place the 1/2 cup of unsalted butter in a 9x13-inch baking dish. Transfer the dish to the preheated oven and allow the butter to melt completely. Once melted, remove the dish from the oven and set it aside.

In a medium bowl, whisk together the flour, remaining 1/2 cup of granulated sugar, baking powder, and salt. Stir in the milk and vanilla extract until the batter is smooth and well combined.

Pour the batter evenly over the melted butter in the baking dish. Do not stir. Spoon the peach mixture over the batter, again without stirring. The batter will rise to the top during baking, creating a delicious crust.

Place the baking dish in the preheated oven and bake for 40-45 minutes, or until the crust is golden brown and the peaches are bubbly. Allow the cobbler to cool for a few minutes before serving.