Yield: 12 servings.

For the cake:
1 cup cake flour
1½ cups granulated sugar, divided
10 egg whites, using large eggs at room temperature, reserve 6 yolks
2 teaspoons vanilla extract
1 teaspoon lemon extract
1½ teaspoons cream of tartar
¼ teaspoon salt
Zest from 2 lemons

For the frosting:
1 stick unsalted butter, at room temperature
5 cups powdered sugar, sifted
1 teaspoon lemon zest
⅓ cup fresh lemon juice
Lemon peel curls (for garnish)

For the cake: Preheat oven to 350°.

Sift together cake flour and ¾ cup of sugar; set aside.

Place egg whites in bowl of standing mixer fitted with a whisk attachment. With mixer on medium-high, add vanilla and lemon extracts, cream of tartar, and salt. Beat on medium to high speed until soft peaks form. Gradually add ¾ cup sugar, beating until stiff peaks form. Sift ¼ cup of the flour mixture over beaten egg whites; fold in gently. Repeat, adding and gently folding in remaining flour mixture ¼ cup at a time. Transfer half of the batter to another bowl.

In a small bowl, beat reserved egg yolks with a hand mixer on high until they’re a pale yellow, 4 to 5 minutes. Fold in lemon zest. Fold egg yolk mixture into one half of divided batter. Into an ungreased 10-inch tube pan, alternate pouring the egg yolk batter and the remaining plain batter. Gently swirl a butter knife through batters to create a marbling effect.

Bake for 40 to 45 minutes or until top of cake springs back when lightly pressed. Remove cake from oven and invert onto a stand or serving plate. Once the cake has cooled completely, run a knife around the edges to loosen from the pan; remove pan.

For the frosting: Using a hand mixer on medium speed in a large bowl, whip butter until light and fluffy. Add powdered sugar, lemon zest, and lemon juice, and continue mixing on medium speed until frosting has a smooth consistency.

Spread frosting over cake and garnish with fresh lemon peel curls.