Preheast oven top 350 degrees. Soak oatmeal in boiling water for 20 minutes. Cream butter, add sugars and beat until fluffy. Add vanilla and eggs, blend. Add oatmeal and beat well. Sifht dry ingredients together and add to oatmeal mixture. mix well. bake in 9x9 square pan 50-55 minutes.
Combine frosting ingredients in saucepan over medium heat. Spread over hot cake. Put under broiler until lightly browned, about 2-3 minutes.