Tis the Season to Make Whoopie

PIES!!!!! (If you're on a New Year diet, just keep one for yourself and share the love with friends and neighbors)
Here's how. You'll need:
To make six CAKES
2 cups of flour
1/2 cup Dutch-processed cocoa powder
1 teaspoon baking soda
1/2 teaspoon salt
8 tablespoons (1 stick) unsalted butter, softened
1 cup light brown sugar
1 large egg, room temperature
1 teaspoon vanilla extract
1 cup buttermilk

To make the FILLING
12 tablespoons (1 1/2 sticks) unsalted butter, softened
1 1/4 cups confectioners' sugar
1 1/2 teaspoons vanilla extract
1/8 teaspoon of salt
2 1/2 cups of Marshmallow Fluff

1. For the CAKES: Adjust racks to upper-middle and lower-middle position and set oven to 350. Line two baking sheets with parchment paper. Whisk the flour, cocoa, baking soda, and salt in a medium bowl.
2. With an electric mixer at med speed, beat butter and brown sugar until fluffy, about 2 minutes. Beat in the egg until incorporated, then beat in the vanilla. Reduce the speed to low and add the flour mixture and the buttermilk in two batches.
3. Using a 1/3 cup measure, scoop six mounds of batter onto each baking sheet, spacing the mounds about 3 inches apart. Bake until the cakes spring back when pressed, 15 to 18 minutes, switching halfway through baking. Cool the cakes completely on the baking sheets, at least 1 hour.
4. For the FILLING: With an electric mixer at med speed, beat the butter and confectioners' sugar together until fluffy, about 2 minutes. Beat in the vanilla and salt. Beat in the Fluff until incorporated. Refrigerate the filling until slightly firm, about 30 minutes. (Can be refrigerated for up to 2 days).
5 Dollop 1/3 cup of the filling on the center of the flat side of six of the cakes. Top with the flat side of remaining six cakes and gently press until the filling spreads to the edge of the cake. (Whoopie pies can be refrigerated in an airtight container for up to 3 days)

This is a new version I tried from the book I gave my mom for her birthday: America's Best Lost Recipes from America's Test Kitchen. It's on page 199. The thing to know about this recipe is that it calls for butter in the frosting rather than Crisco. So if you want to go traditional, go Crisco. If you just want rich, delicious goodness, this will do.