Preheat oven to 180 degrees C. Grease and flour one 25cm ring tin.
Measure the flour, 1 1/2 cups packed brown sugar, biscuit crumbs, baking powder, bicarb soda, salt, ground cinnamon, softened butter or margarine, orange juice and the eggs. Beat until smooth about 2 to 3 minutes. Stir in the walnuts and pour the batter into the prepared pan.
Bake for 45 to 50 minutes or until a toothpick inserted in the centre comes out clean. Let cake stand in pan for 20 minutes. Invert cake onto a serving plate and ice with Brown Sugar Glaze.
To Make Brown Sugar Glaze: Combine the icing sugar, water, 1/2 cup brown sugar and the vanilla. Add more sugar or water to make a proper consistency for a barely pourable glaze.