1. For cake, mix first 6 ingredients. Pour mixture into 8-inch greased pan.
2. Cook in oven for 20 minutes at 350 degrees until inserted toothpick comes out dry.
3. Meanwhile, mix next three ingredients (brown sugar, butter, and milk) in a pot, and bring to boil slowly until brown sugar is melted (2 to 3 minutes).
4. Remove from heat and let cool completely. Then, add powdered sugar, and spread on cooled cake.
