Light as air and delicately rich, this chiffon cake marries the lofty softness of angel food with the tender, moist crumb of an oil-based cake, finishing with an elegant vanilla perfume.
Preheat oven to 325°F (163°C).
Separate 6 eggs while cold, then let the whites and yolks come to room temperature.
Sift together the dry ingredients, including cake flour, baking powder, salt, and about half of the sugar.
In a clean bowl, beat the egg whites with cream of tartar on medium speed until foamy. Gradually add the remaining sugar and beat to stiff, glossy peaks. Set aside.
In a large bowl, whisk the egg yolks, milk, oil, and vanilla until well combined.
Add the sifted dry ingredients to the yolk mixture and whisk until smooth and combined.
Gently fold about half of the meringue into the batter to lighten it, then fold in the remaining meringue just until incorporated, avoiding overmixing or deflating the whites.
Pour the batter into an ungreased 10-inch (25 cm) aluminum tube pan; smooth the top and lightly tap to release large air bubbles.
Bake at 325°F (163°C) until the top springs back when lightly pressed and a tester comes out clean; baking time not specified in the provided excerpt.
Immediately invert the pan and cool the cake completely upside down to prevent collapse.
Once cool, run a thin knife around the edges and center tube to release; remove from the pan.
Serve plain with a dusting of confectioners’ sugar, or with whipped cream and fresh berries; a cream cheese–stabilized whipped cream is suggested in the article as an optional topping.