In a saucepan, add the sliced peaches, sugar, and salt. Stir to combine.

Cook on medium heat until sugar is dissolved. Remove from heat and set aside. 

Preheat oven to 350°F. 

Slice butter into pieces and add to baking dish. Place the pan in the oven while the oven preheats, to allow the butter to melt. Once butter is melted, remove the pan from the oven. 

In a large bowl, mix the flour, sugar, baking powder, and salt for the batter. Add milk and stir until combined. 

Pour mixture into pan, over the melted butter, and spread into an even layer. 

Smooth peaches and juice over the top of the batter and sprinkle with cinnamon.

Bake for 38-40 minutes. 

Serve warm.