Saturday, June 6, 2009

Pucker Up!

Lemon is one of my top flavors (second only to chocolate, of course), but if I'm going to have a lemon dessert, I want it to pack a real punch. No feeble, namby-pamby, lightly-lemon-kissed cake for me, thanks. I want a cake with some zest. So, here's my version of a proper lemon cupcake. The cupcakes are made with lemon zest and juice, then filled with lemon curd, and topped off with a zingy lemon buttercream, which is flavored with the curd. So go ahead, pucker up...

Pucker Up Lemon Cupcakes
Makes 24 cupcakes

Lemon Curd:
8 large egg yolks
1 1/4 cups granulated sugar
2 teaspoons finely grated lemon zest
3/4 cup freshly squeezed lemon juice
Pinch of salt
1/2 cup (1 stick) unsalted butter, cut into tablespoons

Lemon Cupcakes:
3 cups cake flour
2 1/2 teaspoons baking powder
1/2 teaspoon salt
1 cup (2 sticks) unsalted butter, softened
1 3/4 cups granulated sugar
4 large eggs
2 teaspoons finely grated lemon zest
1/4 cup freshly squeezed strained lemon juice
2/3 cup whole milk

Lemon Buttercream:
1 cup granulated sugar
5 large egg whites
3 tablespoons water
2 cups (4 sticks) unsalted butter, slightly softened
1/2 teaspoon vanilla extract
1/2 cup lemon curd

Make the Lemon Curd:
1. Set a fine-mesh sieve over a medium bowl and set aside. In a medium, heavy, non-reactive saucepan, whisk together the egg yolks and sugar until blended. Stir in the lemon zest and juice, salt, and butter and cook over medium heat, whisking constantly, until the mixture thickens, about 7 to 10 minutes (do not let the mixture boil, or it will curdle). The mixture should leave a path on the back of a wooden spoon when you draw your finger across it. Immediately strain the mixture through the sieve, pressing it through with a rubber spatula.
2. Set the bowl containing the lemon mixture in a large mixing bowl filled one-third of the way with ice water (be careful that the water doesn’t splash into the lemon mixture). Stir the lemon mixture frequently until it is slightly chilled, about 15 minutes. Cover the surface of the curd with plastic wrap and refrigerate until ready to use (up to 3 days).

Make the cupcakes:
3. Position a rack in the center of the oven and preheat the oven to 350°F. Line two 12-cup muffin pans with cupcake liners.
4. In a medium bowl, sift together the cake flour, baking powder, and salt. Whisk to combine and set aside.
5. In the bowl of an electric mixer, using the paddle attachment, beat the butter at medium speed until creamy, about 30 seconds. Gradually add the sugar and beat at high speed for 3 minutes, until well blended and light. Scrape down the sides of the bowl with a rubber spatula, reduce the speed to medium, and add the eggs one at a time, beating well after each addition and mixing until blended. Beat in the lemon zest and lemon juice until blended. Reduce the speed to low and add the flour mixture in three additions, alternating it with the milk in two additions. Mix just until blended. Scrape the batter into the prepared cups and smooth the tops.
6. Bake the cakes for 20 to 22 minutes, until they are golden brown around the edges and a toothpick inserted into the center comes out clean. Cool the cupcakes in the pans, set on wire racks, for 15 minutes.
7. Transfer the cupcakes to wire racks and cool completely.

Make the buttercream:
8. Pour enough water into a skillet so that it comes 1/2-inch up its sides. Bring the water to a simmer; reduce the heat to medium-low to maintain a simmer.
9.. In the bowl of an electric mixer, combine the sugar, egg whites, and water. Place the bowl in the skillet of water and whisk gently until the mixture registers 160°F on an instant-read thermometer.
10. Transfer the bowl to the mixer stand and, using the whisk attachment, beat at medium-high speed until the meringue is cool and forms stiff, shiny peaks, about 5 minutes.
11. Reduce the speed to medium and beat in the butter, one tablespoon at a time. Beat in the vanilla. Beat at high speed until the buttercream is smooth, about 1 minute.
12. Add the lemon curd and beat until well blended.

Fill and frost the cupcakes:
13. Using a paring knife, cut a cone-shaped wedge out of the center of each cupcake (the diameter of the cone should be about 1/2 inch).
14. Fill the center of each cupcake with lemon curd.
15. Fill a pastry bag fitted with a medium star tip (Ateco #5) with the buttercream. Pipe a generous swirl of buttercream on top of each filled cupcake. Serve the cupcakes immediately, or refrigerate. Bring to room temperature before serving.