Tangy Orange Frosting
- 2 large egg whites
- 1 cup granulated sugar (7 ounces)
- 1/4 cup fresh orange juice plus 1 teaspoon zest from 2 oranges
- 1 tablespoon corn syrup
- A fluffy, sweet frosting balances the tart lemon filling in this elegant cake.
Combine egg whites, sugar, orange juice, and corn syrup in bowl of standing mixer or large heatproof bowl and set over medium saucepan filled with 1 inch of barely simmering water (do not let bottom of bowl touch water). Cook, stirring constantly, until sugar is dissolved and mixture registers 160 degrees on instant-read thermometer, 5 to 10 minutes. Remove bowl from heat and transfer mixture to standing mixer fitted with whisk attachment. Beat on medium speed until soft peaks form, about 5 minutes. Increase speed to medium-high and continue to beat until mixture has cooled to room temperature and stiff peaks form, 5 minutes longer, adding orange zest during last minute.