In a medium saucepan, add the sliced peaches, 3/4 cup sugar, and 1/4 tsp salt and place over medium heat. Stir to fully coat the peach slices, and cook for a few minutes to let the sugar fully dissolve. The peaches will also release a fair amount of juice, this is normal. Remove from the heat and set aside.
Preheat the oven to 350°F. Slice the butter into 1/2" pieces and place in a 9"x13" baking dish. Place the baking dish in the oven while it preheats to melt the butter. Alternatively, you can melt the butter separately and add it to the baking dish. Once the butter is fully melted, remove the baking dish from the oven.
While the oven is preheating, mix together the sugar, flour, baking powder, and salt in a large bowl. Add the milk and stir just until smooth. Pour the batter into the prepared baking dish, and smooth it with a spatula to get an even layer across the whole pan. It will not fully mix with the melted butter, this is ok.
Spoon the peach slices and juices over top of the batter evenly across the entire surface. Sprinkle the top liberally with ground cinnamon, and then bake for 35-40 minutes. Best served warm with a scoop of ice cream.
Enjoy!
