Created by KittenCal on February 24, 2012
Step 1: Preheat oven to 350 degrees F. Grease a 13 x 9-inch baking pan.
Step 2: In a large bowl combine flour and sugar; set aside.
Step 3: In a medium saucepan combine butter, cola and cocoa powder; cook stirring oven medium heat until the butter melts. Pour over flour mixture. Add in eggs, buttermilk, baking soda and vanilla; mix until thoroughly blended. Stir in marshmallows.
Step 4: Spread the batter evenly into pan. Bake for 30-35 minutes or until cake tests done. Cool completely then frost as desired.