Prepare the peaches - if using fresh, you'll need to peel the peach skins off *see notesIf using canned peaches skip this step and continue to step 2.Place the sliced peaches in a medium size pot with ¾ cup sugar and ¼ tsp salt. Cook the peaches over medium heat, stirring often, until sugar is dissolved and the peaches release some juices (this should only take a few minutes). Remove from heat.
Make Cobbler
Meanwhile, place the butter in a 9x13" baking dish and place in the oven. Preheat the oven to 375 degrees F. allowing the butter to melt in the pan while the oven heats up.
In a separate bowl, combine the flour, sugar, baking powder, and salt and whisk to combine. Pour in the milk and stir just until combined.
Remove the baking dish with the butter from the oven and pour in the cobbler batter. Next, pour the sliced peaches (and any juices) over the batter. Sprinkle with the cinnamon all over the top.
Place the cobbler back into the oven and continue baking for another 30 to 35 minutes, until the cobbler is set. Let the cobbler sit for a few minutes before serving warm. The juices will thicken more as it cools.
Notes
To Quickly Peel Fresh Peaches: Bring a large pot of water to a boil. Add in the peaches a couple at a time to the water and let cook for 30 seconds. Remove the peaches with a slotted spoon and dunk in a bowl of ice water. Once cool, the peach skins will peel off very easily. Frozen Peaches - use 5 cups of frozen peaches as you would fresh peaches - cook slightly with the sugar until juices release.Canned Peaches - do not add extra sugar to the canned peaches, just use from the can (juices too!) and skip the cooking process on the stove top.