Preparation Steps

• Position a rack in the middle of the oven and heat to 375°F (190°C). Lightly grease a 9×13-inch baking dish with a bit of butter or cooking spray.
• In a large bowl, toss the sliced peaches with 1/3 cup granulated sugar and the cinnamon. If you want a thicker filling, stir in the cornstarch. Let the fruit sit while you make the topping — 10 to 15 minutes will help the peaches release their juices.
• Transfer the macerated peaches and any accumulated juices to the prepared baking dish and spread them into an even layer.
• In a medium bowl, whisk together the flour, baking powder, salt and 2/3 cup granulated sugar. Use a fork to combine the dry ingredients until evenly mixed.
• Pour the melted butter and vanilla over the dry mixture. Stir with a wooden spoon or spatula until a shaggy, slightly sticky dough forms — it should resemble a thick drop-biscuit batter rather than a smooth cake batter.
• Drop the topping by tablespoonfuls over the peaches, spacing the dollops 1 to 2 inches apart. Use the back of a spoon or a small offset spatula to gently spread and join some pieces — you want an uneven, rustic surface so juices can bubble up around the dough.
• Sprinkle the turbinado sugar evenly over the top if using. Bake the cobbler, uncovered, for 30 minutes at 375°F. The filling should be bubbly and the topping mostly set.
• Increase the oven temperature to 425°F and continue baking 8 to 10 minutes more, or place under the broiler for 2–4 minutes just until the topping develops golden-brown edges and a bit of crunch. Watch closely to prevent burning.
• Remove from the oven and let the cobbler rest for at least 15–20 minutes so the juices thicken slightly. Serve warm with scoops of vanilla ice cream or a dollop of whipped cream.