Peach-Blueberry Cobbler

Thanks to a combination of a recipe from Patty and a recipe from Allrecipes.com, I made a tasty Peach-Blueberry Cobbler today. I don't especially care for blueberries, but this was really good.

Filling:
5 fresh peaches, peeled, pitted and sliced
1 pint fresh blueberries, picked over
1/4 cup white sugar
1/4 cup brown sugar
1/2 teaspoon cinnamon
2 teaspoons corn starch

Topping:
1 cup all-purpose flour
1/4 cup white sugar
1/4 brown sugar
1 teaspoon baking powder
1/2 teaspoon salt
6 tablespoons unsalted butter, chilled and cut into small pieces
1/4 cup boiling water

Cinnamon Sugar for very top:
1 teaspoon Cinnamon
3 tablespoons white sugar

1. Preheat oven to 425 degrees
2. Combine filling ingredients in a large bowl. Stir to coat and pour into a 2 quart baking dish. Bake for 10 minutes.
3. While the filling is baking, combine all topping ingredients except butter and water. Blend butter into the mix with finger tips or a pastry blender. Mixture should be chunky. Add 1/4 cup boiling water. Stir until just combined.
4. Remove filling from oven and drop spoonfuls of topping over it. Sprinkle with cinnamon sugar. Bake until topping is golden - about 30 minutes.