From the St.Louis Post-Dispatch Let's Eat section (a best of 2006 recipe)
Preheat oven to 375 degrees.
4-5 peaches, peeled and sliced
1 pint blackberries
3 tablespoons dark brown sugar
3 tablespoons all-purpose flour
balsamic vinegar, optional
1 1/4 c all-purpose flour
3/4 c packed dark brown sugar
1 pinch salt
1/2 c chopped toasted nuts, such as almonds, pecans or walnuts
10 tablespoons cold unsalted butter cut into pieces
To prepare topping
Combine flour, sugars, salt, cinnamon, nuts and butter in a food processor; pulse until mixture comes together with a crumbly texture.To prepare filling
Combine berries and peaches in a bowl. Add sugar, flour and a few drops of balsamic vinegar; toss gently. Pour into an ungreased dish big enough to hold the fruit. Place the dish on a baking sheet. Sprinkle fruit evenly with topping. Bake until topping is golden brown and fruit is bubbly, about 1 hour, rotating the pan once.