Pour 1 1/2 cups boiling water over 1 cup quick oats; mix. Let stand 20 minutes in a bowl. Cream 1/2 cup butter, 1 cup brown sugar, and 1 cup white sugar. Beat 2 eggs until foamy and combine with above. Add 1 1/2 cups flour, 1 teaspoon baking soda, 1 teaspoon cinnamon and 1/2 teaspoon salt. Add this mixture to oats. Bake 30 minutes at 350 degrees in a 13x9x2 inch pan. Frost with brown sugar and coconut icing.