This recipe comes from ATK and it is soooo good. It's not runny or super thick. Just right.
Four pounds of frozen sliced peaches can be substituted for fresh; there is no need to defrost them. Start step 2 when the peaches are almost done.
For the filling: Adjust oven rack to middle position and heat oven to 425 degrees.
Melt butter in large oven-safe nonstick skillet over medium-high heat.
Add two-thirds of peaches, sugar, and salt and cook, covered, until peaches release their juices, about 5 minutes.
Remove lid and simmer until all liquid has evaporated and peaches begin to caramelize, 15 to 20 minutes.
Add remaining peaches and cook until heated through, about 5 minutes.
Whisk lemon juice and cornstarch in small bowl, then stir into peach mixture.
Cover skillet and set aside off heat.
For the topping: Meanwhile, whisk flour, 5 tablespoons sugar, baking powder, baking soda, and salt in medium bowl.
Stir in buttermilk and butter until dough forms.
Turn dough out onto lightly floured work surface and knead briefly until smooth, about 30 seconds.
Combine remaining sugar and cinnamon.
Break dough into rough 1-inch pieces and space them about 1/2 inch apart on top of hot peach mixture.
Sprinkle with cinnamon sugar and bake until topping is golden brown and filling is thickened, 18 to 22 minutes.
Let cool on wire rack for 10 minutes.
Serve. (Although best eaten the day it is made to maintain the texture of the cobbles, leftovers may be refrigerated for up to 1 day. Individual portions may be removed from skillet and reheated in microwave or in the oven.).