For a ten-inch cake, melt two teaspoons butter in the skillet before adding batter; bake for thirty-five minutes.
Preheat oven to 400 degrees. In a large bowl, toss peaches with 1/4 cup sugar and 1/2 teaspoon cinnamon; set aside. In a medium bowl, whisk together flour, baking powder, salt, remaining 3/4 cup sugar, and remaining 1/2 teaspoon cinnamon. In another bowl, whisk 4 tablespoons melted butter with milk and egg. Whisk butter mixture into flour mixture.
Melt 1 teaspoon butter in a 6-inch ovenproof skillet over medium heat. Once skillet is hot, remove from heat. Pour one-quarter of batter into skillet. Spread batter evenly over bottom. Spoon one-quarter of peach mixture over batter. Repeat with remaining three skillets. Transfer to oven, and bake until cobblers set, 25 to 30 minutes. Remove from oven; let cool slightly. Serve warm in skillets.