An instant-read thermometer, a kitchen scale and a 2-inch cookie scoop will come in handy for this recipe.
Make Ahead: The unfilled cookies can be stored in an airtight container at room temperature for 3 days, or refrigerate for up to 1 week. Wrap tightly in plastic wrap, seal in a zip-top bag and freeze for up to 3 months. The whipped cream can be made a few hours in advance and refrigerated (give it another quick whisk if it has deflated a bit). The filled cookies are best eaten right away, but can be refrigerated for up to 8 hours in an airtight container. You will have whipped cream filling left over.
- FOR THE COOKIES
- 1 1⁄2 ounces (42 grams) dark chocolate, 60 to 62 percent, chopped
- 1 cup (125 grams) bleached all-purpose flour
- Scant 1/4 cup (19 grams) unsweetened Dutch-process cocoa powder (sift before measuring if using volume)
- 1⁄2 teaspoon baking powder
- 1⁄2 teaspoon baking soda
- 1⁄2 teaspoon fine sea salt
- 2 tablespoons unsalted butter, at room temperature (see headnote)
- 2 tablespoons canola or safflower oil
- 1⁄2 cup plus 1 tablespoon (120 grams) packed dark brown sugar
- 1 large egg, at room temperature (see headnote)
- 1⁄2 cup buttermilk
- FOR THE FILLING
- 1 cup heavy cream
- 1 tablespoon superfine sugar (see headnote)
- 1 teaspoon vanilla extract
Position a rack in the middle of the oven; preheat to 400 degrees. Grease two rimmed baking sheets with cooking oil spray.
About 30 minutes before you start to make the cookies, melt the chocolate in a microwave-safe bowl on HIGH in 15-second increments, stirring in between, until smooth. Let cool until the chocolate is no longer warm to the touch yet still fluid (80 to 85 degrees).
Whisk together the flour, cocoa powder, baking powder, baking soda and salt in a mixing bowl. (If there are lumps from the cocoa powder or baking soda, sift the mixture.)
Combine the butter, oil, dark brown sugar and egg in the bowl of a stand mixer; beat on medium speed for about 5 minutes, stopping to scrape down the sides of the bowl as needed. The mixture should be smooth and paler in color.
Add the melted/cooled chocolate; beat on low speed until well incorporated.
Add one-third of the flour mixture along with one-third of the buttermilk; beat on low speed until just incorporated. Stop to scrape down the sides of the bowl. Repeat with another third of the flour mixture and a third of the buttermilk, and then the final third. Increase the speed to medium; beat for about 15 seconds, until smooth.
Measure the batter into a 2-inch cookie scoop, gently rounded, or use two spoons to drop 6 rounded mounds (about 42 grams each) of batter, evenly spaced onto one of the prepared baking sheets. The mounds should be about 2 inches wide by 1 inch high.
Bake one sheet at a time (middle rack) for 6 minutes, rotating it from front to back. Then bake for 2 to 4 minutes, or just until the caky cookies spring back when pressed lightly with a fingertip.
Allow the batch to cool (on the baking sheet) on a wire rack for 5 to 10 minutes. Then use a thin metal spatula to transfer the cookie cakes directly onto the rack to cool completely.
Meanwhile, scoop the remaining batter onto the second baking sheet; repeat the baking and cooling steps.
For the filling: Combine the heavy cream, superfine sugar and vanilla extract in a medium metal mixing bowl; a handheld electric mixer is easier for this amount of cream. Cover and refrigerate for at least 15 minutes; refrigerate the beaters of the handheld mixer as well. Beat the mixture, starting on low and gradually increasing the speed to medium-high as it thickens, until stiff peaks form.
To assemble the whoopie pies, place a mound of the filling (about 3 rounded tablespoons) on the flat sides of 6 cooled cookies. Press the flat sides of the remaining 6 cookies lightly on top of the filling, just until the filling is forced to the edges. You will not use all the filling.
Serve right away, or refrigerate for up to 8 hours.
Adapted from “Rose’s Baking Basics: 100 Essential Recipes, With More Than 600 Step-by-Step Photos,” by Rose Levy Beranbaum (Houghton Mifflin Harcourt, 2018).
Tested by Becky Krystal; email questions to firstname.lastname@example.org.
Calories: 380; Total Fat: 21 g; Saturated Fat: 10 g; Cholesterol: 70 mg; Sodium: 290 mg; Carbohydrates: 44 g; Dietary Fiber: 2 g; Sugars: 25 g; Protein: 5 g.