Yesterday while visiting my friends who live at the beach in Delaware, we baked eight dozen whoopie pies in seven different flavors: chocolate peanut butter, butterscotch, oatmeal with caramel, oatmeal with butterscotch, strawberry with chocolate chips, strawberry with sprinkles and vanilla raspberry. This kept us quite busy on a dreary and cloudy day. I love that Lancaster, PA is home to the whoopie pie, but now they  are really popular and people are creating creative and yummy recipes! 
Check out this delicious chocolate peanut butter whoopie pie recipe from 
Martha Stewart:
Ingredients
-                                             1 3/4 cups all-purpose flour
 
-                                             3/4 cup unsweetened cocoa powder (not Dutch process)
 
-                                             1 1/2 teaspoons baking soda
 
-                                             1/2 teaspoon fine salt
 
-                                             4 tablespoons unsalted butter, softened
 
-                                             1/4 cup vegetable shortening
 
-                                             1/2 cup granulated sugar
 
-                                             1/2 cup packed dark-brown sugar
 
-                                             1 large egg
 
-                                             1 cup whole milk
 
-                                             1 teaspoon pure vanilla extract
 
-                                             Peanut Butter Buttercream
 
-                                             2 ounces bittersweet chocolate, finely chopped
 
Directions
-                                             Preheat oven to 375  degrees. Line two large baking sheets  with parchment paper; set aside. Sift together flour, cocoa, baking  soda, and salt into a small bowl; set aside.
 
-                                             Add butter, shortening, and sugars to the bowl of an electric  mixer fitted with the paddle attachment; cream on high speed until  smooth, about 3 minutes. Add egg; beat until pale and fluffy, about 2  minutes. Add half the flour mixture, then the milk and vanilla; beat  until combined. Add the remaining flour mixture. Beat together, scraping  down sides of bowl with a rubber spatula as needed.
 
-                                             Drop 12 slightly rounded tablespoons of batter 2 inches apart  on each baking sheet. Bake the cookies in the upper and lower thirds of  oven, 10 minutes; switch the positions of the baking sheets, and rotate  each one. Continue baking until the cookies spring back to the touch, 2  to 4 minutes more.
 
-                                             Remove from oven; let cookies cool on baking sheets, 10  minutes.Transfer with a metal spatula to a wire rack; let cool  completely. Meanwhile, line a cooled baking sheet with a new piece of  parchment; repeat process with remaining batter.
 
-                                             Spread 1 scant tablespoon buttercream on flat sides of half  the cookies.Top each with one of the remaining cookies, flat side down,  and gently press together. Transfer pies to a tray.
 
-                                             Melt half the chocolate in a saucepan over low heat, stirring  until smooth. Remove from heat; add remaining chocolate, and stir until  melted and smooth. Transfer to a pastry bag fitted with a plain round  tip (Ateco #2 or #3) or a small parchment cone. Pipe chocolate in a  spiral pattern on top of each pie. Let chocolate set before serving,  about 1 hour.