Name: Viking Bakery Chiffon Cake
Yield: one 9 × 13 inch sheet, or two 9-inch rounds
Cuisine: United States
Ingredients: 180 g cake flour, sifted; 140 g granulated sugar, for the yolk batter; 10 g baking powder; ⅔ tsp salt; 105 ml vegetable oil; 6 egg yolks; 155 ml cold water; 1¾ tsp vanilla extract; ¼ tsp almond extract (optional); 6 egg whites, very cold; ½ tsp cream of tartar; 75 g granulated sugar, for the whites

Method

Set a rack in the lower third and heat the oven to 325°F. Line the bottom of a 9 × 13 inch pan with parchment for a single sheet about 1 inch thick, or the bottoms of two 9-inch round pans for a two-layer cake. Do not grease the sides; the batter needs to cling as it rises.
Sift the cake flour (180 g1½ cups), granulated sugar (140 g⅔ cup), baking powder (10 g2½ tsp) and salt (⅔ tsp) into a large bowl.
In a separate bowl, whisk the egg yolks (6), water (155 ml⅔ cup), oil (105 ml7 tbsp), vanilla (1¾ tsp) and the almond extract if using, until pale and frothy, about 30 seconds. Add to the dry ingredients and whisk until smooth.
In a clean bowl, beat the egg whites (6) with the cream of tartar (½ tsp) on medium until foamy and starting to hold soft peaks. Only then add the granulated sugar (75 g6 tbsp) a spoonful at a time, beating to stiff, glossy peaks that stand upright but don't look dry or clumpy.
Fold the whites into the yolk batter in three additions: stir the first third in firmly to loosen the batter, then fold in the second and third gently with a cutting motion. A few white streaks are fine.
Pour into the pan or pans, spread evenly, and run a knife through the batter to release large air pockets. Bake until the top springs back when pressed and a toothpick comes out clean: 25 to 32 minutes for the 9 × 13, about 25 to 30 minutes for the rounds. Don't overbake; chiffon dries out faster than butter cakes.
Cool completely in the pan, then run a knife around the edges to release.

Notes

Water or milk. Water gives the softest, most tender crumb. The same amount of whole milk gives a slightly richer, slightly firmer cake.
Serving. Good with whipped cream and berries, a thin glaze, or Ermine Buttercream. Day-old chiffon slices more cleanly.
Tall tube-pan chiffon. This batch is sized for a sheet. A classic tall chiffon in an ungreased 10-inch tube pan needs roughly 1⅓ times the recipe (8 eggs, 240 g flour), a longer bake at 325°F, checking from about 50 minutes, and cooling upside down in the pan. This version hasn't been tried.
This is the cake under Classic Petit Fours Glacés, where milk replaces the water for a firmer crumb that cuts cleanly.