Step 1: Preheat your oven to 375°F (190°C). Place the butter in a 9x13 inch baking dish and put it in the oven to melt while it preheats.
Step 2: In a medium saucepan, combine the sliced peaches, brown sugar, cinnamon, and lemon juice. Cook over medium heat for about 5 minutes until the sugar dissolves and the peaches release their juices.
Step 3: In a large mixing bowl, whisk together the flour, granulated sugar, baking powder, and salt. Add the milk and stir until just combined. Do not overmix.
Step 4: Remove the baking dish from the oven. Pour the batter over the melted butter. Do not stir.
Step 5: Spoon the peach mixture (including the syrup) evenly over the batter. Again, do not stir.
Step 6: Bake for 40-45 minutes or until the crust is golden brown and a toothpick inserted into the crust comes out clean.
Step 7: Let the cobbler cool for at least 10 minutes before serving warm with ice cream or whipped cream.