Preheat oven to 375°F. Lightly spray an 8x8-inch square baking dish with cooking spray.
Alternatively, you can use four 5-inch mini cast iron skillets. Set aside.
In a medium bowl, combine the sugar, nutmeg, and cinnamon. Add peaches and blueberries and toss to coat. Pour fruit mixture into prepared baking dish.
To make the topping, in a separate bowl, combine the oats, cereal, flour, brown sugar, butter and cinnamon.
Stir to mix well until crumbly. Sprinkle topping over fruit mixture.