Red Velvet Whoopie Pies

These are a recipe Baylie makes and they're very yummy.

2 c. flour
2 Tblsp. Dutch processed cocoa
1/2 tsp. baking soda
1/4 tsp. salt
1/2 c. butter, softened
1 c. packed brown sugar
1 egg
1 tsp. vanilla
1/2 c. buttermilk
1 (1-ounce) bottle red food coloring
(If you double this recipe, don't double the food coloring, just add
2 Tblsp. milk)
Filling:
1/2 c. softened butter
8 oz. softened cream cheese
7-oz. marshmallow cream
1/2 c. powdered sugar

Preheat oven to 375 degrees.  Line baking sheets with parchment; set aside.  In a medium bowl combine flour, cocoa powder, baking soda and salt; set aside.
In a large mixing bowl, beat butter on medium to high 30 seconds. Beat in brown sugar until light and fluffy.  Beat in egg and vanilla.  Alternately add flour mixture and buttermilk, beating after each
addition just until combined.  Stir in food coloring.
Spoon batter in 1 or 2 inch diameter rounds about 1/2 inch high on prepared baking sheets, allowing 1 inch between each round.  Bake 7 to 9 minutes for 1-inch or 9 to 11 minutes for 2 inch cookies, or until tops are set.  Cool completely on baking sheets on rack.  Remove cooled cookies from baking sheets. 
To fill, dollop Whoopie Pie Filling on flat sides of half the cookies. 
Top with remaining cookies, flat sides together.
Whoopie Pie Filling:
In a medium mixing bowl beat 1/2 c. softened butter and 8 ounces softened cream cheese until smooth.  Fold in one 7-ounce jar marshmallow cream & 1/2 c. powdered sugar.
Refrigerate cookies in airtight container up to 4 days.  Let stand at room temperature 15 minutes before serving.