Rhubarb Streusel Cake with Vanilla Sauce

I had some Rhubarb in the fridge that needed to be used, so I decided to try a new recipe.  I didn't have enough white sugar, so I substituted with brown sugar for most of the recipe.  The cake is alright, but it is the sauce that makes it taste so good.  My husband and daughter loved it.  Because I used brown sugar, the sauce tasted more like a Carmel sauce.  I wouldn't make the cake by itself to eat without the sauce. 

Do you have any good recipes that you would like to share?