Lemon Cupcakes with Lemon Curd and Raspberry Filling

For lemon curd:
3/4 cup sugar
1/4 cup plus 1 tablespoon lemon juice
1/2 stick butter
4 large egg yolks
1 tablespoons (packed) grated lemon peel
1/8 teaspoon salt

For lemon syrup:
1/4 cup sugar
6 tablespoons fresh lemon juice

For the icing:
1 tablespoons lemon juice
1/2 cup plus 2 tablespoons confectioners' sugar, sifted
1 tablespoon warm water

For cake:
1 1/2 cups cake flour
3/4 teaspoon cream of tartar
3/8 teaspoon baking soda
1/8 teaspoon salt
3/4 cups and 2 tablespoons sugar
1 stick unsalted butter, room temperature
4 large egg whites, whisked until blended but not foamy
1 teaspoons vanilla extract
1/2 cup evaporate whole milk
cupcake liners (the kind with both metal and paper)

1 pint fresh raspberries

To make curd:
Combine first 4 curd ingredients in large microwave-safe bowl. Place bowl in microwave and cook on high until butter melts, whisking every minute, about 3 minutes. Remove from microwave; cool 5 minutes. Beat eggs in small bowl to blend. Whisk half of butter mixture into eggs. Return mixture to same large bowl. Place in microwave and cook on high until curd is slightly thickened but not boiling, whisking every minute, about 4 minutes (curd will continue to thicken when chilled). Transfer curd to medium bowl. Press plastic wrap onto surface. Chill until firm, at least 8 hours.

To make lemon syrup:
Combine sugar and lemon juice in small bowl. Whisk until sugar dissolves.

To make cake:
Preheat oven to 375.

Sift flour, cream of tartar, baking soda and salt into medium bowl. Beat sugar and butter in large bowl until fluffy. Add egg whites in 2 additions, beating well after each addition. Beat in vanilla. Beat dry ingredients into butter mixture alternately with milk, beginning and ending with dry ingredients.

Place paper cupcake liners in pan, reserving metal liners to use later. Fill liners about 2/3 full. Bake until golden and tester inserted into center comes out clean, about 12-15 minutes (check by pushing lightly on top of cupcake with finger, if it leaves a dent, they need to cook longer, if it pops back remove from oven. You can also use a toothpick and poke it to see if it comes out clean). Transfer cupcakes to racks and cool completely.

To make icing:
Whisk the lemon juice into the confectioners' sugar first, then slowly mix in the water.

To assemble:
Remove cupcakes from liners. Using unwaxed, unflavored dental floss, cut cupcakes in half horizontally. Poke tiny holes in halves using a fork and pour a little lemon syrup over cupcakes. Place cupcake bottom in metal liner and spread a little lemon curd over the cupcake. Place a few raspberries over curd and place cupcake top over filling. Drizzle glaze over cupcake and garnish with berries.