Here it is: 

1 c. coca-cola
1/2 c. buttermilk
1 c. butter or margarine, softened
1 3/4 c. sugar
2 large eggs, lightly beaten
2 t. vanilla extract or 1 t. almond extract
2 c. all-purpose flour
1/4 c. cocoa
1 t. baking soda
1 1/2c. miniature marshmallows
GARNISH:  3/4 c. chopped nuts, toasted

FROSTING:

1/2 c. butter or margarine
1/3 c. coca-cola
3 T. cocoa
1 (l6 oz.) pkg powdered sugar or 2 c. powdered sugar
1 T. vanilla extract

COMBINE the cola and buttermilk; set aside.

BEAT butter at low speed with mixer, until creamy.
Gradually add sugar; beat till blended.

ADD eggs and vanilla; beat at low speed until blended.

COMBINE flour, cocoa and soda.  ADD to butter mixture
alternately with cola mixture; begin and end with
flour mixture.  BEAT at low speed just until blended.

STIR in marshmallows by hand ( do NOT use mixer for
this).

POUR into a greased and floured or Pam Sprayed 13X9
pan.

BAKE at 350 degrees F. for 30-35 minutes.  Remove from
oven; cool 10 minutes while preparing frosting.

Pour frosting over warm cake; garnish with nuts, if
desired. 

FROSTING:  Bring butter and cola to a boil in a large
saucepan over medium heat, stirring until better
melts.  Removed from heat; whick in sugar and vanilla.

POUR over warm cake.

ENJOY!!!!!   I know I always do