Whoopie Pie Cake

Great for Parties or Pot Lucks
1 box Chocolate cake mix + 1 extra egg
cocoa powder for dusting the pan
1 cup butter, room temperature
2 cups Marshmallow Fluff 
3 cups powdered sugar
1/2 cup heavy cream...

1 cup semisweet chocolate chips

Preheat oven to 350°. Grease a 9x13" pan and line the bottom with parchment wrap and grease and use cocoa powder to dust the pan, too...or you can grease 2 9x13 sized pans with butter and dust with cocoa powder, set aside. Prepare cake according to package directions, but add in an extra egg to the mix. Pour the batter into the pan and bake 30-35 or until a toothpick inserted in the center comes out clean...OR Split the batter evenly between the 2 pans and bake for 15-20 minutes until a toothpick comes out clean. Allow cakes to cool completely.  If using one cake, divide in half, top to bottom.

In a stand mixer, beat butter and Fluff together until smooth. Turn mixer to low and slowly add the powdered sugar. Turn mixer up and continue mixing for 30-60 seconds until smooth. Spread the filling on top of one of the cakes {or layer}. Top the filling with the other cake. In small saucepan bring the heavy cream almost to a boil. Remove from heat and stir in chocolate chips. Allow to cool for 10 minutes and then pour over top of cake.