Preheat oven to 350F. Toss apples, sugar and salt together. Divide equally among 4 individual oven proof bowls, ramekins or gratin dishes. Combine butter and flour with fingertips until mixture is crumbly and has the texture of oatmeal. Add brown sugar, allowing lumps to remain in mixture. Distribute evenly over apples. Bake 30 minutes. Serve warm or cold with a scoop of vanilla ice cream.
