This easy Smores Cake has ribbons of marshmallow, graham cracker, and chocolate in a rich fudge cake. Get that irresistible s'mores flavor in every bite!
In a large bowl, mix together cake mix, 3 eggs, 1 stick of butter, 2 tsp vanilla extract, and 1 cup of milk. Spread in the bottom of a greased 9x13" glass dish.
Spoon half of the marshmallow fluff and half of the tub of chocolate frosting over the cake mix. With a spoon, gently swirl the two into the batter. You don't want to mix; you should still see separate swirls of marshmallow fluff, frosting, and cake batter. Make sure you swirl the mixture to the end of the pan.
Mix together remaining marshmallow fluff and chocolate frosting, not totally blending so there are still swirls throughout. Frost cake with this mixture.
Crush the remaining graham crackers into fine crumbs. Mix with 2 tablespoons of butter. Sprinkle these graham cracker crumbs over the top of the frosting.