Sour Cream Rhubarb Cake

1 1/2 c. sugar
1/2 c. melted butter
1 egg
1 c. sour cream
1 tsp. vanilla
1 tsp. baking soda
2 c. flour
1 1/2 c. rhubarb

Topping:
1/3 c. sugar
1 tsp. cinnamon

1. Preheat oven to 350 F.
2. Grease 9x13 pan and set aside.
3. Melt butter and allow to cool a bit.
4. In large bowl, combine sugar, butter, egg, sour cream and vanilla. Mix well.
5. Stir in the baking soda and flour.
6. Fold in rhubarb.
7. Spread batter in pan.
8. In small bowl, combine the sugar and cinnamon. Sprinkle over the batter and bake for 40-45 min.