Preheat oven to 350 degrees Fahrenheit. Combine sugar, milk and oil in mixing bowl. Add the eggs and then the flour, baking soda, salt, vanilla and rhubarb. Mix well.
Pour mixture into a well-greased 8-1/2 by 4-1/2 inch loaf pan. Sprinkle the sugar over the top and dot with the butter.
Bake for one hour, or until the bread is firm to the touch. Allow to cool for 10 minutes and then turn out onto a wire rack to cool completely.