Considering my undying love affair for whoopie pies, it was only a matter of time before I let myself get creative with them. I blame my other half for my infatuation mostly because it wasn’t until I ventured north into the great state of Maine that I became acquainted with them (and then obsessed with them). In Maine they are ubiquitous, the way cupcakes are to NYC. Some versions are the size of my head (really they are and really I may have eaten the whole thing), some have fillings that veer into the buttercream family (not my favorite) and some are utter perfection. While I will always hold the traditional chocolate cake one with a marshmallow fluff center as the best of the best, I am willing to test some new flavor combinations in an effort to allow some of the others to enter the running.
These whoopie pies came about after a bout of inspiration and a lot of starring at the zucchini sitting on the counter taunting me. The inspiration came from one of my most favorite cakes (this zucchini olive oil cake that will forever be one of the best things I’ve ever eaten) and with that as the starting point, these emerged. I like to think of these as a grown up version of a childhood favorite. The combination of spiced cake with a fluffy marshmallow frosting is undeniably addicting which makes these the perfect treat for a picnic lunch or a dessert for a fancy dinner party.
Zucchini Whoopie Pies
Makes about 12 whoopie pies
2 cups coarsely grated zucchini (10 ounces)
2 1/2 cups all-purpose flour
1 1/4 teaspoons baking soda
1 1/2 teaspoons ground cinnamon
3/4 teaspoon ground ginger
1/2 teaspoon ground nutmeg
1/2 teaspoon salt
3/4 cup well-shaken buttermilk
1 teaspoon pure vanilla extract
1 stick unsalted butter, softened
1 cup packed light brown sugar
1 large egg
1 stick (1/2 cup) unsalted butter, softened
1 1/4 cups confectioners sugar
2 cups marshmallow cream such as Marshmallow Fluff (homemade recipe below)
1 teaspoon vanilla
Make cakes: Preheat oven to 350°F with racks in upper and lower thirds. Butter 2 large baking sheets.
Squeeze handfuls of zucchini wrapped in a kitchen towel to remove moisture.
Whisk together flour, baking soda, spices, and salt until combined. Whisk together buttermilk and vanilla in a small bowl.
Beat together butter and brown sugar in a large bowl with an electric mixer at medium-high speed until pale and fluffy, about 5 minutes. Add egg and beat until combined well. At low speed, mix in flour and buttermilk mixtures alternately in batches, beginning and ending with flour mixture and mixing until smooth. Mix in zucchini until just incorporated.
Spoon 1/4-cup mounds of batter 2 inches apart on baking sheets. (These spread A LOT so give the batter a lot of space.) Bake, switching position of sheets halfway through, until tops are puffed and golden and spring back when touched, 18 to 22 minutes. Transfer with a spatula to a rack to cool completely.
Make filling: Beat together butter, confectioners sugar then add in the marshmallow fluff, and vanilla in a bowl with electric mixer at medium speed until smooth, about 3 minutes.
Spread a rounded tablespoon filling on flat sides of half of cakes and top with remaining cakes.
Cakes can be made 3 days ahead and kept, layered between sheets of wax paper, in an airtight container at room temperature.
Filling can be made 4 hours ahead and kept, covered, at room temperature. Refrigerate if you aren’t going to use it before then.
Makes 2 cups
3 egg whites
2/3 cup sugar
2/3 cup sugar
Make a double boiler by bringing a small pot of water to a bare simmer, then place the bowl of your stand mixer, if you’ve got one, or another large stainless steel bowl atop the water. Add the egg whites and sugar, and whisk continuously until the sugar dissolves and the liquid is warm to the touch.
Transfer the bowl from the stovetop to your stand mixer (you’ll probably want to wipe the condensation from its bottom before securing), and use the whisk attachment to whip the liquid on medium-high speed until it turns glossy with stiff peaks, about 8 minutes. If you don’t have a stand mixer, do the same with your electric hand mixer.
Eat immediately or refrigerate for no more than a week.