You can make an easy berry dessert using just four ingredients. Start with fresh or frozen berries, mixing them in a baking dish. For the topping, combine oats, flour, sugar, and butter until crumbly. Sprinkle this mixture over the berries. Bake at 350°F for about 25 minutes, or until the topping is golden brown. This dish is under 300 calories, packed with fiber and antioxidants, making it a healthy choice. Serve it warm with ice cream or chill it for a rejuvenating snack. There are also many ways to customize it, so you can explore various options for personal flavor.