Preheat your oven to 350°F
Melt the butter in a 9x13-inch baking dish in the oven.
Mix the flour, sugar, and milk together until smooth.
Pour the batter over the melted butter (don't stir).
Spoon the peaches and syrup evenly over the batter (again, don't stir).
Bake for 35-45 minutes, or until the crust is golden brown.