Ingredients
2 cups all-purpose flour, (spooned and leveled)
4 teaspoons baking powder
1/2 teaspoon salt
1 1/2 cups sugar
1/2 cup vegetable oil, such as safflower
6 large eggs, separated
2 tablespoons finely grated orange zest and 1/2 cup fresh orange juice (from 2 to 3 navel or Valencia oranges)
1/4 teaspoon cream of tartar
Candied Orange Zest for Orange Chiffon Cake, optional
1 cup heavy cream
1 tablespoon sugar
1/2 teaspoon pure vanilla extract
Preparation
Preheat oven to 325 degrees. In a large bowl, whisk together flour, baking powder, salt, and 1 cup sugar. Make a well in center of flour mixture. Add oil, egg yolks, orange zest and juice, and 1/4 cup cold water; whisk batter until smooth.
Using an electric mixer, beat egg whites and cream of tartar until soft peaks form. Gradually add remaining 1/2 cup sugar (1 tablespoon at a time); continue to beat until stiff peaks form. Using a rubber spatula, gently fold half of egg-white mixture into batter. Fold in remaining egg-white mixture just until combined (do not overmix).
Pour batter into a 10-inch footed angel-food cake pan with a removable bottom; bake until a toothpick inserted near center of cake comes out clean, 55 to 60 minutes. Remove from oven; invert, still in pan, onto a baking sheet. Cool completely. Run a knife around edge and center to release cake. Serve topped with vanilla whipped cream and candied orange zest, if desired.
