1 3/4 c. brown sugar, packed
1/2 c. oil
1 egg
2 tsp. vanilla
1 c. buttermilk
1 1/2 c. rhubarb, diced
1/2 c. chopped nuts
2 1/2 c. flour
1 tsp. baking soda
1 tsp. baking powder
1/2 tsp. salt

In mixing bowl, combine first 5 ingredients and beat well. With spoon, stir in rhubarb and nuts.

In separate bowl, combine dry ingredients; stir into rhubarb mixture just until blended. Spoon batter into 20 greased, medium sized muffin cups, filling 2/3 full.

For topping, combine 1/3 cup sugar, 1 teaspoon cinnamon and 1 tablespoon melted butter. Sprinkle over filled cups and press lightly into batter. Bake at 400 degrees for 20-25 minutes.