Mimosa Cake with Lemon Frosting

1 . Stage

Preheat the oven to 375 degrees F (190 degrees C).

2 . Stage

Sift flour and 1/2 cup sugar together onto a piece of waxed paper.

3 . Stage

Combine all 10 egg whites, cream of tartar, and salt in a large glass, metal, or ceramic bowl. Beat at high speed until foamy. Gradually add remaining sugar, 1 tablespoon at a time, until soft peaks form. Fold flour mixture into the meringue, 1/3 at a time, until completely blended.

4 . Stage

Beat 4 egg yolks in a small bowl with an electric mixer on high speed until thick and lemon colored. Beat in lemon zest and vanilla. Fold 1/2 of the meringue batter into the egg yolk mixture until no streaks of white remain.

5 . Stage

Alternating between the two batters and without stirring or mixing, spoon tablespoonfuls into an ungreased 10-inch fluted tube pan (such as Bundt®).

6 . Stage

Bake in the preheated oven until the top springs back when lightly pressed with a fingertip, about 35 minutes.

7 . Stage

Remove from the oven and invert onto a quart-sized soft drink bottle; cool completely, about 30 minutes.

8 . Stage

Loosen cake around the edge and tube with a spatula. Cover pan with a serving plate; turn upside down, shake gently, and remove cake from the pan. Frost with lemon frosting.