Preheat oven to 350 degrees F. Melt the stick of butter in a 9x13 inch baking dish in the oven. Once melted, remove the pan from the oven.
In a large bowl mix together the flour, sugar, baking powder, cinnamon, and salt. Stir in the milk, and vanilla extract just until combined. Pour the mixture into the pan, on top of the melted butter. Make an even layer.
Spoon the peaches and juice (or canned peaches) over the batter. My grandmother would put one peach pit right in the middle. She says it was her secret ingredient. Remove the pit when serving.
Bake at 350 degrees for about 38-40 minutes. The crust should be golden brown and edges look crispy. Serve warm, with a scoop of ice cream, if desired.
Notes
To substitute canned peaches, use 2 cans of peaches but the juice from one can. If you have canned peaches in syrup, use 1 quart. Stirring in peach jam works too.