Gather all ingredients.
Preheat the oven to 425 degrees F (220 degrees C).
Combine peaches, 1/4 cup white sugar, 1/4 cup brown sugar, 1/4 teaspoon cinnamon, nutmeg, lemon juice, and cornstarch in a large bowl; toss to coat evenly, and pour into a 2-quart baking dish. Bake in preheated oven for 10 minutes.
Meanwhile, combine flour, 1/4 cup white sugar, 1/4 cup brown sugar, baking powder, and salt in a large bowl. Blend in butter with your fingertips or a pastry blender until mixture resembles coarse crumbs. Stir in water until just combined.
Remove peaches from oven, and drop spoonfuls of topping over them.
Mix 3 tablespoons white sugar and 1 teaspoon cinnamon together in a small bowl; sprinkle over entire cobbler.
Bake in the preheated oven until topping is golden and the fruit filling is bubbling around the edges, about 30 minutes.
