Ruth's Rhubarb Coffee Cake

I found a Rhubarb coffee cake recipe on the Internet but decided to change it up to make it my own recipe. I made it today and am happy with the end product. I would do a tad less sugar. So I have adjusted it in this recipe.

cake batter
1/2 cup margarine or butter, softened
3/4 - 1 cup sugar
2 eggs
1 tsp Vanilla
1 tsp baking soda
1 tsp. baking powder
1 tsp. cinnamon
1/2 tsp. nutmeg
1/4 tsp. cloves
1/4 tsp salt
2 cups flour
1 cup sour milk  (add 1-2 tbsp. lemon juice or vinegar to 1 cup milk)
3 cups finely chopped Rhubarb
1 cup walnut crumbs

Topping
1/4 cup cold margarine or butter
1 cup brown sugar
2 tsp. cinnamon
1/4 cup flour

Cream together butter and sugar. Add Vanilla and eggs. Beat well. Add soda, powder, salt and spices. Mix well. Add flour alternately with milk. Mix well. Add nuts and Rhubarb. Pour into a 9x13 greased pan.
Crumble together topping and drop onto batter. Bake at 350F for 45-50 minutes or till toothpick comes out clean. If you use a metal pan remove cake to another container when cake is cooled as the Rhubarb may rust  your metal  pan if it is scratched or cake will take on a metallic taste. I use glass pans and really like them. I would not go back to metal!
YIELD: 9X13 pan