There is something a little magical about a whoopie pie: two soft, cocoa-rich cakes hugging a cloud of fluffy marshmallow filling in between. Part cookie, part cake, and entirely nostalgic, they are the kind of treat that disappears from the counter the moment they cool. These come together with a chocolatey crumb and a filling that is rich but never too sweet, thanks to a mix of marshmallow fluff, butter, and whipped egg whites.
Total Time:1 hour 15 minutes
Yield:8 whoopie pies
Ingredients
Cakes
2 cups(240g) all-purpose flour
½ cup (60g) cocoa powder
1 tsp. baking soda
1 tsp. baking powder
1 tsp. salt
1 tsp. espresso powder
½ cup butter, softened
1 cup (200g) sugar
1 cup buttermilk
2 egg yolks, pasteurized (save whites for filling)
1 tsp. vanilla extract
Filling
1 cup butter, softened
1¼ cups (150 grams) confectioners’ sugar, divided- 1 cup (120 grams) for filling, ¼ cup (30 grams) for egg whites
2 cups (256 grams) marshmallow fluff
2 tsp. vanilla extract
¼ tsp. salt
2 egg whites, pasteurized
⅛ tsp. cream of tartar
Instructions
Cakes
Preheat oven to 350°F and line two baking sheets with parchment paper.
In a medium bowl, sift together the flour, cocoa powder, baking soda, baking powder, salt, and espresso powder.
In a large bowl, cream the butter and sugar. Add the egg yolks and vanilla.
Continue mixing on low speed, alternating adding the buttermilk and the flour mixture. Scrape the sides as needed.
Cover and chill the mixture in the refrigerator for 30 minutes.
Scoop ¼ cup of batter (an ice cream scooper works well here) onto the baking sheets, spacing 3 inches apart.
Bake for 13–15 minutes, until the tops are puffed and a toothpick inserted into one of the cakes comes out clean.
Cool completely on a wire rack.
Filling
In a large bowl, whip the butter, 1 cup confectioners’ sugar, marshmallow fluff, vanilla, and salt until smooth.
In a separate bowl, beat the egg whites with the cream of tartar until stiff peaks form. Fold in the remaining ¼ cup confectioners’ sugar.
Add the egg white mixture to the butter mixture and whip for about 1–2 minutes, until light and fluffy.
Spread the filling onto the flat side of one cake and top with a second cake to sandwich.
Wrap individually and store in an airtight container.
Notes
This filling uses raw egg whites. Be sure to use pasteurized eggs, especially if serving to kids, pregnant women, or anyone with a weakened immune system.
Of the 1¼ cups confectioners’ sugar, only 1 cup is blended into the filling base. Save the remaining ¼ cup to fold into the beaten egg whites.
The cream of tartar helps stabilize the egg whites, so they whip up light and hold their peaks.
Cakes can be baked a day ahead. Store unfilled at room temperature in an airtight container, then fill before serving.
