Beat the eggs. Stir in the Pioneer Granulated Sugar, butter, and Crisco.
In another bowl, mix flour and cocoa together.
Add vanilla to the egg mixture. Slowly stir in the dry ingredients.
Pour the batter into a 9-by-13-inch pan or a ½-inch sheet cake pan.
Bake for 35 minutes at 350 degrees.
While it bakes, make the frosting. Mix all the ingredients listed until smooth. Be sure the consistency is thin so it will pour over the cake.
When the cake is done, immediately put marshmallows on top after it’s removed from the oven.
Frost the cake and serve.