Preheat oven to 400°F. Lightly grease a 9-inch cast iron skillet or similar sized casserole/baking dish. Place the dish on a foil lined rimmed sheet pan and set aside.
Peel and thick slice the peaches and place in a large bowl. Drizzle with lemon juice and toss to coat. Set aside.
In a medium saucepan stir together the sugar and cornstarch. Slowly whisk in the boiling water. Heat over medium-high and bring the mixture to a boil, stirring frequently. Boil one minute stirring constantly until very thick. Remove from the heat and add the peaches, any peach juice, butter and cinnamon. Stir gently to combine. Pour the peaches into the prepared baking dish. Set aside.
To prepare the shortcake dough:
In a medium mixing bowl whisk together the flour, sugar, baking powder and salt. Add the butter to the flour mixture. Using a pastry blender, cut-in the butter until it resembles a coarse meal. Add the cream and stir gently with a rubber spatula just until incorporated.
Using your fingers or a spoon dollop pieces of the shortcake dough randomly on top of the peaches leaving some open space. Brush each dough mound with cream then sprinkle with coarse sugar. Allow the cobbler to rest for 10-15 minutes before baking.
Bake for 25-35 minutes or until the cobbler is golden brown and the fruit is bubbling and syrupy. Serve warm with ice cream. The sauce will thicken more when cooled.
Notes
Add 1 extra tablespoon of cornstarch for a thicker sauce.
Store leftovers in the refrigerator for up to 4 days. Rewarm in the microwave on 50% power to desired temperature.
You can use frozen peaches in place of fresh. No need to thaw first.
Nutrition information is calculated using an ingredient database and should be considered an estimate. When multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.