Rhubarb Crumble Cake

My rhubarb is growing like mad so I cut some the other day to make a cake with. Here's the delicious recipe.

RHUBARB CAKE

Serve cold or warm with cream, marscapone, custard or icecream.
Dust with icing sugar for presentation.
Ingredients:
1 1/2 cups sugar
115g butter or margarine (or 1/3 cup rice bran oil or vegetable oil)
1 egg
2 cups plain flour
½ tsp salt
1 tsp vanilla
1 tsp bicarb soda
1 cup sour milk (add 1 Tbspn vinegar to milk)
3 cups rhubarb, peeled and finely chopped (1 bunch)

Topping: 1/2 cup brown sugar (or raw sugar)
½ cup rolled oats
1 heaped Tbs softened butter or margarine
Method:
Place all ingredients, except rhubarb in bowl and beat well until combined.
Add rhubarb and fold into mixture
Put mixture into a baking paper lined square tin or a greased baking dish.
Mix topping ingredients together and sprinkle evenly over cake
Bake at 180C for approx. 1 hour or until ready when tested with a skewer.

Superb dessert.