In a medium sized pot, bring 1 1/2 cups of water to a rolling boil and add 1 cup of raw oatmeal; cook until all the water has been absorbed by the oatmeal; remove from heat, and set aside.
In a clean bowl cream together softened butter with brown and white sugar. Add 2 eggs to the butter and sugar mixture and beat in cooked oatmeal. Sift together all remaining dry ingredients and add to the cooked oatmeal mixture, add vanilla extract, and gently blend together.
Lightly grease a 11 by 7-inch pan with a little butter or margarine. Lightly dust greased pan with flour, make sure you get the corners and the sides of the pan. Line the bottom of the pan with parchment paper. Gently pour batter onto the parchment lined pan and level batter into an even layer. Bake in oven for approximately 15 to 20 minutes. You’ll know it’s done when it is firm to the touch and the cake no longer jiggles. Remove from oven and allow to cool slightly.
While cake is cooling, prepare frosting by placing a small- to medium sized dry non-stick pan over medium heat. Add 1/2 cup of sweetened shredded coconut to the dry pan and gently toast until golden, make sure
you continually stir so it doesn’t burn. In a small bowl, add almost all of the toasted coconut (save a little for decoration after baking), softened butter, brown sugar, and heavy cream, mix together until the sugar has melted.
Cover the cake with the frosting mixture, set the oven to the broiler setting, and move the baking rack to the second highest position. Place your frosted cake into the oven for approximately 1 minute or until frosting begins to bubble all over. Remove from oven and allow the cake to cool. Garnish with the remaining toasted coconut.