Classic Whoopie Pies

Ingredients

Equipment Needed

• •Electric hand mixer or stand mixer
• •Large cookie scoop (2 tablespoon capacity)
• •Two rimmed baking sheets
• •Wire cooling racks

Instructions

1. 1

   Bloom the cocoa

   Position racks in the upper and lower thirds of your oven and preheat to 375°F. Line two baking sheets with parchment paper. Whisk together the flour, cocoa powder, baking soda, and salt in a medium bowl. Pour the hot coffee over the cocoa mixture and whisk until smooth. The cocoa will bloom, releasing a deep, almost fruity chocolate aroma. Set aside to cool slightly.

   Dutch-process cocoa matters here. Its alkalized nature produces a darker color and richer flavor than natural cocoa. Don't substitute.
2. 2

   Cream butter and sugar

   Beat the softened butter and brown sugar in a large bowl with an electric mixer on medium-high speed until light and fluffy, about 3 minutes. The mixture should look pale and increase noticeably in volume. Scrape down the sides of the bowl. Add the egg and vanilla, beating until fully incorporated, about 1 minute more.

3. 3

   Build the batter

   Reduce mixer speed to low. Add the flour-cocoa mixture in three additions, alternating with the buttermilk in two additions, beginning and ending with the dry ingredients. Mix just until combined after each addition. The batter will be thick, glossy, and deeply chocolate-colored. Resist the urge to overmix. Tender rounds depend on a gentle hand here.

   Room temperature buttermilk incorporates smoothly. Cold buttermilk can cause the batter to look curdled and produce uneven texture.
4. 4

   Portion the rounds

   Using a large cookie scoop or two tablespoons, drop mounds of batter onto the prepared baking sheets, spacing them 2 inches apart. You should get about 24 rounds total. Each mound should be roughly the same size for even pairing later. Don't flatten them. They'll spread and dome on their own.

5. 5

   Bake until springy

   Bake for 10 to 12 minutes, rotating the pans halfway through, until the tops spring back when lightly pressed and a toothpick inserted in the center comes out clean. The rounds will look matte, not shiny, when done. Transfer the pans to wire racks and let the rounds cool on the pans for 5 minutes before moving them directly to the racks. Cool completely before filling. This takes about 30 minutes. Patience.

6. 6

   Make the marshmallow filling

   While the rounds cool, beat the butter for the filling in a clean bowl with the electric mixer on medium-high speed until pale and creamy, about 2 minutes. Add the marshmallow creme and beat until fully combined and fluffy, scraping the bowl as needed. Reduce speed to low and add the powdered sugar, vanilla, and salt. Increase speed to medium-high and beat until the filling is light, smooth, and spreadable, about 2 minutes more. It should hold soft peaks.

   Sifting the powdered sugar prevents lumps in your filling. Nothing ruins the smooth experience of a whoopie pie like gritty filling.
7. 7

   Assemble the whoopie pies

   Match the cooled rounds into pairs of similar size. Turn half of them flat-side up. Dollop a generous 2 tablespoons of filling onto each flat side. Don't spread it to the edges yet. Place a second round on top, flat-side down, and press gently until the filling spreads to within a quarter inch of the edge. You want filling visible around the perimeter. That's the mark of a proper whoopie pie.

8. 8

   Rest before serving

   For the best texture, let assembled whoopie pies rest at room temperature for 30 minutes before serving. This brief rest allows the filling to set slightly and the flavors to meld. The rounds will soften just enough to yield easily when you bite through. Serve at room temperature for maximum enjoyment.

Chef Tips

• •Seek out Marshmallow Fluff rather than generic marshmallow creme if you can find it. The Fluff brand, made in Massachusetts since 1920, has a lighter texture and cleaner flavor that genuine New Englanders insist upon.
• •If you don't have buttermilk, make a quick substitute: stir 1 tablespoon of white vinegar or lemon juice into 1 cup of whole milk and let it sit for 5 minutes until slightly thickened.
• •The coffee can be regular or decaf. Its purpose is to bloom the cocoa and deepen the chocolate flavor, not to add caffeine. The coffee taste disappears entirely in the finished product.
• •These freeze beautifully. Wrap assembled whoopie pies individually in plastic wrap, then store in a freezer bag for up to 2 months. Thaw at room temperature for 30 minutes before serving.

Advance Preparation

• •Unfilled cake rounds can be stored in an airtight container at room temperature for up to 2 days, or frozen for up to 1 month.
• •Marshmallow filling can be made up to 3 days ahead and refrigerated. Bring to room temperature and re-whip briefly before using.
• •Assembled whoopie pies keep at room temperature in an airtight container for 3 days, or refrigerated for up to 1 week. Bring to room temperature before serving for the best texture.

Frequently Asked Questions

Nutrition Information

1 serving (about 65g)