Lemon Raspberry Cake

Lemon curd:

1. In large metal bowl, whisk together eggs, sugar, lemon juice, and butter. Set bowl over pot of simmering water and cook, whisking frequently, until mixture is thick enough to coat the back of wooden spoon, about 20 minutes. Immediately force curd through fine-mesh sieve into large bowl, scraping bottom of sieve. Press plastic wrap directly onto surface of curd to prevent skin from forming and chill until cold, at least 1 hour. (Curd can be made ahead and refrigerated up to 1 week before serving.)

Meringue buttercream:

1. In medium heavy saucepan, combine 1/2 cups sugar and 2 tablespoons water. Set over low heat and stir until sugar dissolves. Raise heat to high and boil syrup, undisturbed, until candy thermometer registers 240°F, occasionally washing down sugar crystals on side of pan with pastry brush dipped in cold water.
2. While sugar is boiling, in bowl of electric mixer fitted with whisk attachment, beat egg whites until they just hold soft peaks. Slowly beat in remaining sugar, then beat until whites just hold stiff peaks.
3. Decrease speed to medium. Beat in hot syrup in slow, steady stream (try to avoid beaters and side of bowl), then beat until stiff, glossy peaks form and mixture is completely cool, about 8 to 10 minutes (the bottom of the mixing bowl should be cool to the touch).
4. With mixer on medium, beat in butter, 1 piece at a time, and beat until thickened and smooth. (Mixture will break at first, but, as more butter is beaten in, will thicken and become glossy and smooth.) Beat in vanilla.
5. Assembly (cake-lemon-raspberries-cake-lemon-cake-lemon-raspberries-cake-buttercream)
6. Place one layer on plate. Spread 1/3 lemon curd over cake. Arrange half raspberries, side by side, stem ends down, atop curd in concentric circles to cover entire layer. Top with second layer, gently pressing layers together. Spread another 1/3 lemon curd atop second layer, then cover with third layer, gently pressing layers together. Spread remaining 1/3 lemon curd atop third layer. Arrange remaining half raspberries, side by side, stem ends down, atop curd in concentric circles to cover entire layer. Top with fourth layer, gently pressing layers together.
7. Using spatula and about 1/3 buttercream, spread thin, even coat of frosting on top and sides of the cake. Refrigerate tiers until frosting is firm, about 30 minutes.
8. Using spatula and remaining buttercream, evenly spread second, slightly thicker (about 1/8-inch-thick) layer of frosting on top and sides of the cake. Refrigerate tiers at least 2 hours or overnight.