Preheat oven to 350F. Peel and core apples, if using. Cut peaches or apples into 1/2-inch wedges and place i n a bowl. Sprinkle with cinnamon and toss until evenly coated. If using peaches, mix in berries. (Blueberries will turn the apples gray.) Press down firmly in a 9-inch pie plate. In a medium-sized bowl, stir flour with rolled oats and brown sugar.Slowly add gutter, working in with a fork. Carefully mound on top of fruit and gently press into surface. Bake in centre of preheated oven for 60-70 minutes or until fruit is tender when pierced with a skewer. This crisp is wonderful served warm with ice cream or yoghurt cheese.