01 - Preheat oven to 375°F. Lightly grease a 9x13-inch baking dish.
02 - In a large mixing bowl, combine sliced peaches, granulated sugar, brown sugar, lemon juice, cinnamon, nutmeg, cornstarch, and a pinch of salt. Toss gently until peaches are thoroughly coated.
03 - Spread the prepared peach mixture evenly into the greased baking dish.
04 - In a separate bowl, whisk together flour, granulated sugar, baking powder, and salt. Add cold cubed butter and cut into dry ingredients using a pastry cutter or fingertips until mixture resembles coarse crumbs.
05 - Pour in milk and vanilla extract. Stir gently until just combined. Dough should be soft and slightly sticky; do not overmix.
06 - Spoon dollops of biscuit dough over the fruit, leaving spaces between to allow steam to escape.
07 - Evenly sprinkle remaining granulated sugar over biscuit topping. Bake for 40 to 45 minutes, or until biscuit crust is golden and fruit is bubbling at the edges.
08 - Let cobbler cool for at least 15 minutes before serving. Enjoy warm, optionally with vanilla ice cream.