I didn't grow up eating Whoopie Pies like many of my New England neighbors did. I grew up in California and never heard of a whoopie pie until I moved to the East Coast. But had I known how easy they are to make, I would have started baking them years ago!
The origin of the Whoopie Pie is hotly contested. New Englanders believe it was invented in Maine (a handful of accounts even suggest Boston). Pennsylvania residents believe it was invented by Amish women in the Pennsylvania Dutch Country. The controversy cannot be resolved because written records of Whoopie Pie Recipes do not go back as far as the treat itself has been around. Either way, they were invented sometime around the mid-1920s according to most accounts.
Whoopie Pie is not a pie at all. It is two pieces of cake (originally chocolate) baked on a flat tray like a cookie, then sandwiched together with filling inside. That filling is either a marshmallowy filling or a heavier frosting like buttercream, depending on what region you get your whoopie from. I personally like to use a Seven Minute Icing and I think this was probably the original filling. I'm no food historian, but my own pet theory is that these treats were originally just a way to use up leftover cake batter and leftover frosting. And since boiled icings like the classic Seven-Minute Icing were very popular in the 1920s, that could easily have been what they used. It has a marshmallowy taste, which could be where the whole marshmallow filling idea came from.
But whatever the origins, they are really good and so easy to make! You DO NOT need a special Whoopie Pie Pan to make these. They are supposed to be made on a cookie sheet.
Cake:
2 cups Flour
2/3 Cup Cocoa Powder (I like SACO brand, which is a blend of natural and dutch process)
1 1/4 teaspoons Baking Soda
1 teaspoon Salt
1 Cup Buttermilk (shake well before measuring it out)
1 1/2 teaspoons Vanilla extract
1/2 Cup Butter, softened
1 Cup packed Brown Sugar
1 Egg
For Filling:
Seven-Minute Icing
Preheat oven to 350 degrees. Spray 2-3 cookie sheets with non-stick spray.
Mix together the Flour, Cocoa powder, Baking Soda, and Salt until well-combined. In a separate Bowl, mix together the buttermilk with the vanilla.
Put the butter and sugar in a mixing bowl and beat for a few minutes at medium speed until light and fluffy. Add the egg and beat again until the egg is mixed in. Then, on low speed, add the flour mixture alternating with the buttermilk, adding them in batches (start and end with the flour). Scrape down the bowl and then mix again on low until everything is well-blended.
Use a standard-sized Ice Cream scoop to scoop out the batter onto your greased cookie sheets, a couple of inches apart. (Use a mini-scoop or a standard teaspoon to do mini whoopie pies). Bake for 10-13 minutes (less for minis) until tops are rounded and firm to the touch, springing back when you touch them with your finger. I like to switch the cookie sheets in the oven halfway through baking time, so they bake evenly.
Cool on a wire rack before filling with the Seven-Minute Icing (above) or a buttercream if you prefer.
