Whisk sugar, flour, cocoa, eggs,vanilla and salt into chocolate mixture. Pour into a greased 15x10x1 inch jelly-roll pan.
Bake at 350 for 20 minutes. Remove from oven and sprinkle evely iwth ninature marshmallows; bake 8-10 minutes or until golden brown.
Drizzle warm cake with chocolate Frosting, and sprinkle evenly with toasted pecans.