Prep the oven and pan: Heat the oven to 375°F (190°C). Place the stick of butter in a 9x13-inch baking dish and put it in the oven to melt. Keep an eye on it so it doesn’t brown too much.

Prepare the peaches: In a bowl, combine sliced peaches, ½ cup granulated sugar, brown sugar (if using), lemon juice, cornstarch, cinnamon, and nutmeg. Toss gently until the peaches are coated and glossy.

Make the batter: In another bowl, whisk flour, ½ cup granulated sugar, baking powder, and salt. Add milk and vanilla extract. Whisk until smooth and pourable—no need to overmix.

Assemble: Remove the baking dish with the melted butter. Pour the batter directly over the butter—do not stir. Spoon the peach mixture and all its juices evenly over the batter. Again, don’t mix; the batter will rise up around the fruit as it bakes.

Bake: Place the dish on the center rack and bake for 40–50 minutes, until the top is golden brown and set, and the peach juices are bubbling thickly around the edges.

Rest briefly: Let the cobbler sit for 10–15 minutes. This helps the juices thicken and makes scooping cleaner.

Serve: Spoon warm cobbler into bowls and top with a big scoop of vanilla ice cream. The contrast is the magic here.