Preheat oven to 425. Combine filling ingredients in a large mixing bowl. Mix until peaches are well coated. Pour into a 2-quart baking dish. Bake for 10 minutes.
Meanwhile, place dry ingredients for topping (except 1 Tablespoon of white sugar) in a large mixing bowl. Stir until combined. Cut in butter using a pastry cutter, until mixture resembles coarse meal. Stir in boiling water until combined. Mixture will sticky (similar to dumpling batter). Remove peaches from the oven. Drop spoonfuls of topping over peaches. Sprinkle with 1 Tablespoon white sugar.
Bake for 20-25 minutes, or until topping is golden brown.