Preheat oven to 350~. Combine brown sugar, oil and beaten egg. In a small bowl mix together milk, baking soda, salt and vanilla. Add milk mixture to sugar mixture alternately withflour, beating well after each addition. Fold in rhubarb and nuts. Turn into 2 greased and floured 8x4x3 inch loaf pans. Mix topping ingredients and sprinkle on top of loaves. Bake about one hour or until toothpick inserted in center of bread comes out clean.
