Heat the oven to 350°F. Place the butter in a 9 by 13-inch baking dish. Put the dish in the oven so the butter melts as the oven heats (efficiency!).
In a bowl, mix the flour and sugar together. Strain the syrup from the peaches, and measure out 1/4 cup syrup (if you don't have enough, supplement with water). Add the syrup to the flour-sugar mixture, along with the milk. Stir until smooth.
Take the pan with the melted butter out of the oven. Pour the batter over the butter, then arrange the peaches on top. You can do this as intentionally or as rustic as you like.
Bake for 50 to 60 minutes, until the batter rises around the peaches and the edges are crispy and golden. Serve warm with one of three creams: whipped cream, drizzle of heavy cream, or ice cream.