This is a rich dessert that works well for company since you can make it ahead and warm up before serving. Rum and raisins add a spectacular twist to old fashioned apple crisp.
Cut the chilled butter into the oatmeal, sugar, salt, and flour, with a pastry blender or blend in food processor until it is like coarse crumbs; set aside.
Toss butter with apples, raisins soaked in rum, cinnamon and nutmeg.
Transfer apple mixture to a greased (with butter) baking dish and top with walnut s and flour topping; Sprinkle more walnuts on top.
Bake for 45 minutes or until crisp.
Serve hot or warm with ice cream or whipped cream.