Preheat oven to 350 degrees.
Make the topping: In a small bowl, combine oats, walnuts and salt. In another bowl combine honey and oil. With a fork stir honey and oil into oat mixture.
Make crumble: In a blender or food processor, pulverize vanilla bean with the sugar. In a bowl toss together vanilla sugar with remaining crumble ingredients. Pour into buttered 6 cup dish. Sprinkle with topping and bake for 35 minutes until juices are bubbling and topping is golden brown. Serve immediately alone or over vanilla yogurt.
Recipe courtesy of Gourmet Magazine