Diary of a Secret Housewife: Lemon Whoopie Pies

After a week of 80+ degree weather, we're back to dreary and rainy days here in Boston.  But you know the saying: when life gives you lemons, make lemonade . . . or, better yet, lemon whoopie pies.

As you know (from here and here), I adore whoopie pies, but I find many whoopie pies too sweet.  So when I happened upon this lemon whoopie pie recipe from the fabulous Joy the Baker, I knew I had to make it: the tartness of the lemons make this a grown-up whoopie pie (if that's not an oxymoron).  To amplify the contrast between the tartness of the lemons and the sweetness of the cake and frosting, I added lime zest and subtracted some sugar from the frosting.  These whoopies taste like my favorite childhood candy, Lemonheads.

Ingredients:

For the cookies:

• 1 1/2 cups all-purpose flour
• 1/2 teaspoon baking powder
• 1/4 teaspoon baking soda
• 1/4 teaspoon salt 
• 6 Tablespoons (3/4 stick) unsalted butter, at room temperature
• 1 cup sugar
• 1 teaspoon finely grated lemon zest
• 1 large egg
• 1 Tablespoon fresh lemon juice
• 1 teaspoon vanilla extract
• 1/2 cup buttermilk

Lemon Cream Cheese Filling

• 6 Tablespoons (3/4 stick) unsalted butter, at room temperature
• 6 ounces cream cheese, at room temperature (I like the texture of whipped cream cheese the best for frostings)
• 1 teaspoon vanilla extract
• 1 teaspoon finely grated lemon zest
• 1 teaspoon finely grated lime zest
• 2 Tablespoons lemon juice
• 2 cups powdered sugar (more to taste, if you like)

Position a rack in the middle of the oven.  Preheat the oven to 350 degrees F.  Line two large baking sheets with parchment paper and butter the paper.

Sift together the flour, baking powder, baking soda, and salt into a medium bowl and set aside.  In a stand mixer, beat the butter, sugar and lemon zest until smooth.  Add the egg, lemon juice and vanilla.  On low speed, add half of the flour mixture, mixing just to incorporate it.  Add the buttermilk.  Mix in the remaining flour mixture just until it is incorporated and the batter looks smooth.

Using a ice cream scooper or a spherical measuring spoon, drop about 1 to 1.5 tablespoons of dough onto the baking sheets.  You should get about 24 medium-sized cookies (enough for 12 whoopie pies).  Refrigerate the dough balls for 15 minutes or so before baking; this will help the whoopies hold their domed shape.  (I made my first batch without refrigerating the dough, and as you can see from the photos, many of the whoopie pies turned out flat.)  Bake the cookies one sheet at a time until toothpick inserted in the center comes out clean and the tops feel firm, about 12 minutes.  Joy says that with the exception of the edges, the tops of the cookies should not brown.  Cool the cookies on the baking sheets for 10 minutes, then use a wide spatula to transfer them to a wire rack to cool completely.

Meanwhile, make the frosting.  At low speed, beat the butter, cream cheese, vanilla, lemon zest, lime zest, and lemon juice until thoroughly blended and smooth, about 1 minute.  Add the powdered sugar and mix until smooth.  Chill frosting in the refrigerator for about 30 minutes.

Assemble the whoopie pies by sandwiching about 1.5 tablespoons of filling between two cookies. Wrap each cookie in plastic wrap and refrigerate for at least 1 hour.  Serve cold.  Joy says that the wrapped cookies can be stored in the refrigerator for up to 4 days, but I doubt you'd have any leftover after day 1!