lemon cake with whipped topping

the goods:

cake:
1 cup (2 sticks) unsalted butter, room temperature, plus more for pans
2 and 1/2 cups all-purpose flour
1 tablespoon lemon zest
1/2 teaspoon baking powder
1/2 teaspoon baking soda
1 teaspoon salt
1 and 1/2 cups sugar
2 large eggs plus 3 large egg yolks
2 tablespoons fresh lemon juice
1 cup buttermilk

candied lemons:
1/2 cup sugar
1 thinly sliced and seeded lemon
1/4 cup fresh lemon juice

whipped frosting:
3 large egg whites
3/4 cups sugar
2 tablespoons fresh lemon juice



Preheat oven to 350 degrees. Butter and flour two 8-inch cake pans, tapping out excess flour. In a medium bowl, whisk flour, lemon zest, baking powder, baking soda, and salt.



In a large bowl, using an electric mixer, beat butter and sugar until light and fluffy. With mixer on low, beat in eggs and yolks, one at a time. Alternately beat in flour mixture and buttermilk with lemon juice, beginning and ending with flour mixture; mix just until combined.



Divide batter between pans; smooth tops. Bake until cakes pull away from sides of pans, 32 to 35 minutes.



While cakes are baking, bring 1/2 cup sugar and 1/2 cup water to a boil in a saucepan. Add lemon slices and simmer 25 minutes. Using a slotted spoon, transfer lemon slices to a waxed-paper-lined plate. Stir lemon juice into syrup.



Let cool in pans 10 minutes. Run a knife around edges of pans and invert cakes onto a wire rack. Using a toothpick, poke holes in warm cakes on rack. Brush with lemon syrup. Let cool completely.



While cakes cool, make whipped topping: In a heatproof bowl set over (not in) a saucepan of simmering water, combine egg whites, sugar, a pinch of salt, and 1/3 cup water. Cook over medium, stirring constantly, until sugar has dissolved, 2 to 3 minutes. Transfer to a large bowl. Using an electric mixer, beat on medium-high until glossy, stiff peaks form; reduce speed to low and add lemon juice. Beat just until combined.



Place one cake, bottom side up, on a cake stand or platter. Spread top with whipped topping.



Top with remaining cake; frost top, then sides.





Top with candied lemons. Serve within a few hours.