FIRST Preheat oven to 375°F. Grease a 9-inch baking dish with butter or cooking spray and set aside. In a small bowl, combine sugar, cornstarch, and allspice. Combine peaches and berries in a large bowl and toss with sugar mixture. Spread evenly into baking dish and set aside.
NEXT In a medium bowl, combine flour, sugar, cinnamon, and 1/4 teaspoon salt. Using the back of a fork, incorporated butter into flour mixtures until it resembles small peas. Stir in pecans and spread mixture evenly over fruit.
LAST Bake for 45-50 minutes until fruit is bubbly and crust is golden brown. Serve with fresh whipped cream or vanilla ice cream if desired.