1 12 oz bag chocolate chips, divided (go for the Ghirardelli*)
6 tablespoons butter
6 tablespoons milk
1½ cups sugar
½-3/4 cup chocolate chips (Ghirardelli again, please)
½-3/4 cup mini marshmallows*
Preheat oven to 350. With an electric mixer, cream the butter and sugars. Add the eggs and mix well.
Add flour, soda, salt and cocoa and mix until just incorporated. The batter will be very thick.
Add water to oatmeal and let stand for a few minutes. Once oats are soft, add oats/water mixture to the batter and mix well. Stir in half of the bag of chocolate chips (6 ounces).
Pour into a greased or buttered rectangular 9x13 cake pan. Sprinkle the top of the cake with the rest of the bag of chocolate chips (6 ounces).
Bake at 350 for 30-40 minutes or until the surface springs back lightly when touched and your house smells amazing. Do not overbake. Let cool completely.
For the frosting, melt the butter, sugar, and milk in a large saucepan over medium-low heat. Bring to a boil and boil for 30 seconds.
Reduce heat to low and add chocolate chips and marshmallows. Stir or whisk until frosting is smooth. Pour immediately over the cooled cake. The frosting crystallizes almost immediately as it cools so it's important to get it on the cake while it's still piping hot. Allow the frosted cake to cool for 5 minutes before serving. Or... not.
*You can substitute rolled oats for the quick cooking oats, but they should be soaked in the boiling water for at least 10 minutes. Also, if you use rolled oats, the texture of the cake will be different as the oats will be more noticeable.
*Any chocolate chips will work.
*Regular size marshmallows work, too. They just take longer to melt.
Recipe by Pinch of Yum at http://pinchofyum.com/the-worlds-best-chocolate-oatmeal-cake