Preheat oven to 375° F. Set 8 4-ounce canning jars or ramekins on a baking sheet. For one large crisp, use a 9-inch pie plate.
Pit peaches and peel if desired. Slice or cut into chunks.
1 1/2 pounds peaches
Make the filling. In a large bowl stir together granulated sugar, the 2 tablespoons flour, and 1 teaspoon cinnamon. Add peaches and blueberries; stir well to coat. Divide filling among the jars.
1/4 cup granulated sugar, 2 tablespoons gluten-free flour blend, 1 teaspoon ground cinnamon, 2/3 cup fresh blueberries
For topping, in a bowl stir together brown sugar, remaining flour, rolled oats, pecans, and remaining cinnamon. Using a pastry blender or two knives, cut in butter until mixture resembles coarse crumbs. Sprinkle topping evenly over the peach mixture. (You may have extra topping; store in the freezer for a future use.)
1/3 cup packed brown sugar, 1/4 cup gluten-free flour blend, 3 tablespoons gluten-free rolled oats, 1 to 2 tablespoons chopped pecans, 1/8 teaspoon ground cinnamon, 3 tablespoons salted butter
Bake, uncovered, for 25-30 minutes or until topping is golden brown and juices are bubbling. Let cool for 10 minutes before serving.
If not serving immediately, let cool to room temperature, then cover the jars with the canning lids and store in the refrigerator or freezer, then reheat in the oven before serving for about 10 minutes.