1teaspoonlemon extract (I use Nielsen-Massey Lemon Extract
For the frosting:
8large egg whites
1 1/3cupgranulated sugar
1/2teaspooncream of tartar
Preheat oven to 350 degrees.
In a large bowl, mix the cake mix, eggs, water, oil and lemon extract with a hand mixer until well blended, approximately 1-2 minutes. Line a cupcake pan with paper liners and fill each liner halfway with batter. Bake for 19-22 minutes or until a toothpick inserted into the center comes out clean. Transfer to a wire rack and cool to room temperature.
While the cupcakes are baking, make the frosting.
Fill a saucepan with a few inches of water and bring to a boil. Fit a mixing bowl in the pan and make sure it's not touching the water. Remove the bowl and whisk the egg whites, sugar, lemon juice and zest, cream of tarter and salt in the bowl by hand. Place the bowl above the boiling water and continue whisking until the mixture until the sugar dissolves, about 1 to 2 minutes. Transfer the mixture to a standing mixer fitted with the whisk attachment and beat at medium-high speed until meringue has cooled and holds stiff peaks have formed, about 5-7 minutes.
Using a melon baller, remove the center of each cupcake and save the tops. Fill a zip top bag with the lemon curd and cut off a corner. Fill each cupcake with lemon curd so the top is level, do not overfill. Place the reserved cupcake tops over the meringue.
Fill a pastry bag with the frosting and pipe the frosting onto the cupcake (or use an off-set spatula to frost your cupcakes.) Lightly toast the frosting with a kitchen torch, if desired.