Cream together shortening, sugar, eggs, vanilla and add cooled oats with dry ingredients.
Bake at 350 degrees for 25 minutes or until butter knife inserted in the middle comes out clean.
Topping: melt the butter until its bubbly, add the brown sugar and bring to a boil, slowly add in the milk and again bring to a boil, remove from the heat, mix in the vanilla and the coconut and frost the warm cake.
Put back in the oven for 5 minutes.
Recipe by Amish 365 at https://www.amish365.com/amish-peanut-butter-rolled-oats-cake/