Preheat your oven to 350°F (175°C).
In a large bowl, mix sliced peaches with half of the sugar and let them sit for about 10 minutes.
In another bowl, combine flour, baking powder, salt, and remaining sugar.
Add melted butter and milk to the dry ingredients, stirring until just combined.
Pour the peach mixture into a greased baking dish.
Spoon the batter over the peaches evenly.
Sprinkle with cinnamon if desired.
Bake in the preheated oven for 35-40 minutes until golden brown.
Allow to cool for a few minutes before serving.
Serve warm with ice cream or whipped cream.