Pre-heat oven to 350°F Butter or nonstick cooking spray can be used to grease a 9x13-inch baking pan
You can make the cake! Combine the 1/2 cup of cocoa powder and the melted butter in a large bowl until it is well blended. Blend in the sugar, eggs, and vanilla. Add flour and salt.
Add the nuts. Place the batter in a pan.
Bake for 35 minutes, or until a toothpick comes clean.
Bake the cake. While the cake is baking, prepare the chocolate toppingg. Set aside.
Sprinkle marshmallows on top of the cake after it is taken out of the oven. Bake for three minutes more. The marshmallows will begin to soften and melt.
After removing the marshmallow-cake from the oven, spread the chocolate topping on top of the cake in small mounds. Mix the chocolate topping and softened marshmallows together. Flakey salt and additional nuts may be added. Let cool, then serve. Enjoy!