2 Cups all-purpose flour
1 Cup packed brown sugar
1/2 Cup unsweetened cocoa powder
1 tsp baking soda
1 Cup buttermilk
1 large egg, slightly beaten
6 tbsp unsalted butter, melted
1 can (12 ounces) whipped vanilla frosting
1.Use parchment paper to line 2 cookie sheets
2.Combine dry ingredients in medium sized bowl. Whisk just to blend.
3.Stir in buttermilk, egg and melted butter. Stir with a wooden spoon until just blended.
4.Spoon mixture into gallon size bag and cut 1/2 inch from the corner and pipe 3 1/2 x 1 inch logs about 2 inches apart on cookie sheet. (should fit 12 per sheet)
5.Bake at 350 for 12-14 minutes, or until firm to the touch.
6.Transfer to cooling racks and let cool completely.
7. In another bag, spoon in frosting. Pipe some of the frosting onto one cookie and sandwich with another. Continue with remainder of cookies.