Preheat oven to 375 degrees. Lightly butter a 8-inch square baking dish. Pare, core, and thinly slice the apples, arrange in prepared pan. Sprinkle the apples with the lemon juice. Spread the dried cranberries over the apples. Combine the flour, brown sugar, salt, nutmeg and cinnamon. Add the butter and with a fork or pastry blender, combine until the butter is cut into small pieces and the mixture is crumbly. Stir in the walnuts. Spread the crumb topping over the sliced apples. Bake 30 - 35 minutes, or until golden brown and bubbly. Serve warm with ice cream or whipped cream.