Preheat the oven to 350 degrees F (175 degrees C). Place butter in a deep 2-quart baking dish and place in oven to melt.

Mix sugar and flour in a medium bowl. Stir in milk, a little at a time, until fully incorporated. Pour carefully over melted butter in the dish. Spoon peaches and syrup over batter.

Bake in the preheated oven until crust is puffed and golden, about 35 to 45 minutes.