For cupcakes:
3 c all-purpose flour
1 tbsp baking powder
1/2 tsp salt
1 c unsalted butter, room temperature
2 c sugar
4 large eggs, room temperature
Finely grated zest of 3 lemons(about 3 tbsp), plus 2 tbsp fresh lemon juice
1 tsp pure vanilla extract
1 c buttermilk
Preheat oven to 325 degrees. Line muffin tray with liners. Whisk together flour, baking powder, and salt.
With electric mixer on med-high speed, cream together butter and sugar until pale and fluffy. Add eggs, one at a time, beating until each is incorporated, scraping down sides of the bowl as needed. Beat in zest and vanilla. Add flour mixture in three batches, alternating with two additions of buttermilk and lemon juice, and beating until just combined after each.
Divide batter evenly among lined cups, filling each three-quarters full. Bake, rotating tins halfway through, until golden brown and a tooth pick inserted in center comes out clean, about 25 minutes. Transfer tins to wire wracks to cool completely before removing cupcakes.
For Lemon Curd:
2 whole eggs plus 8 egg yolks
1 c sugar
2/3 c fresh lemon juice(about 6 lemons)
2 tbsp unsalted butter, cut into small pieces, room temperature
Combine whole eggs and yolks, sugar and lemon juice in a heatproof bowl set over a pan of simmering water. Cook, whisking constantly, until mixture is thick enough to coat the back of a spoon. Remove from heat. Add butter, a few pieces at a time, whisking until smooth after each addition. Strain through a fine sieve into another bowl, and cover with plastic wrap, pressing in directly on surface to prevent a skin from forming. Refrigerate until chilled and fir, at least 2 hours (or up to 2 days).
1 1/2 c plus 2 tbsp sugar
2/3 c water
2 tbsp light corn syrup
6 large eggs
Combine 1 1/4 c sugar with the water and corn syrup in a small saucepan: clip a candy thermometer to the side. Bring to a boil over medium heat, stirring occasionally, until sugar dissolves. Continue boiling, without stirring, until syrup reaches 230 degrees.
Meanwhile, in the bowl of a mixer fitted with the whisk, whisk egg whites on med-high until soft peaks form. With mixer running, add remaining 2 tbsp of sugar, beating to combine
As soon as sugar syrup reaches 230, remove from heat. With mixer on med-low, pour syrup down side of bowl in a slow, steady stream. Raise speed to med-high and whisk until mixture is completely cool(test by touching the bottom of the bowl) and stiff peaks form, about 7 minutes. Use immediately.
To assemble:
Spread 1 tbsp lemon curd onto middle of each cupcake. Fill a pastry bag fitted with large open star tip(wilton#8B or Ateco#828) with frosting. Pipe with frosting. Hold a small kitchen torch 3 t 4 inches from surface of frosting, and wave it back and forth until lightly browned. Serve immediately.
Source: Martha Stewart's Cupcakes Book
