In a mixing bowl, combine the brown sugar and flour. Cut in the butter to a fine crumble. With your hands work th dough to form a moist ball.
Pat the dough out into the bottom of a buttered In a 12 inch Dutch oven ad 12-inch cast iron skillet or a 9x13-inch casserole dish. Bake with coals until the dough sets up, or if cooking indoors at 350 degrees F (uncovered) for 15 minutes.
Return the peaches to the heat and bring back to a boil. Stir in the cornstarch and cook until thickens slightly, stirring frequently.
Pour the peaches over the crust and drizzle over the maple syrup.