This recipe contains no raw egg, no shortening or oil, it's all butter baby. I have tried another zaar recipe for whoopie pies, but I like this one. It is from Cook's Country.com. Don’t be tempted to bake all the cakes on one baking sheet; the batter needs room to spread in the oven.
03Whisk flour, cocoa powder, baking soda, and salt in medium bowl.
04With electric mixer on medium speed, beat sugar and butter in large bowl until fluffy, about 4 minutes. Beat in egg until incorporated, scraping down sides of bowl as necessary, then beat in vanilla.
05Reduce speed to low and beat in one-third of flour mixture, then half of buttermilk. Repeat with half of remaining flour mixture, then remaining buttermilk, and finally remaining flour mixture. Using rubber spatula, give batter final stir.
06Using 1/3-cup measure, scoop 6 mounds of batter onto each baking sheet, spacing mounds about 3 inches apart.
07Bake until cakes spring back when pressed, 15 to 18 minutes, switching and rotating pans halfway through baking.
08Cool completely on baking sheets, at least 1 hour.
09For the filling:
10With electric mixer on medium speed, beat butter and sugar together until fluffy, about 2 minutes.
11Beat in vanilla and salt. Beat in Fluff until incorporated, about 2 minutes. Refrigerate filling until slightly firm, about 30 minutes. (Bowl can be wrapped and refrigerated for up to 2 days.)
12Dollop 1/3 cup filling on center of flat side of 6 cakes. Top with flat side of remaining 6 cakes and gently press until filling spreads to edge of cake.
13Whoopie pies can be refrigerated in airtight container for up to 3 days.