Step 1

Preheat the oven to 325°F. Have the 10" angel food cake at hand.

Step 2

In a large mixing bowl fitted with a paddle attachment, combine the flour, 1 cup of sugar (200 grams), baking powder and salt.  Mix to combine.  .

Step 3

Add the oil, egg yolks, juice, vanilla and zest.  Mix for about 1 or 2 minutes until well combined. Set aside.

Step 4

In a clean mixing bowl fitted with the whisk attachment, add the egg whites, remaining 1/2 cup of sugar (100 grams) and the cream of tartar. Beat on low to mix, raise the speed to medium and beat until very foamy, then raise to high and beat until medium peaks. The peaks should not bend over as in soft peaks, nor should the be as stiff as for a meringue,

Step 5

Pour the whites over the flour mixture and fold together. To fold in, plunge a plastic spatula into the center of the egg whites all the way to the bottom. Scoop up some of the flour mixture and bring it up to the top, turning the spatula over to deposit it. Turn the bowl about an eighth of a turn and continue in this manner until the two are mixed.

Step 6

Pour the batter into the unprepared angel food pan and level it. Bake for 45 to 50 minutes until medium brown, it springs back when lightly touched or a tester comes out clean.

Step 7

Immediately, turn it upside down to cool if the pan has feet or hang it on a soda or beer bottle to cool.

Step 8

When completely cool, go around the sides of the pan with a small, flexible metal spatula, keeping the spatula to the edge of the pan, not the cake. Release the center tube in the same manner. Remove the side.

Step 9

To remove the bottom, place a spatula between the metal bottom and the cake. Go around the whole bottom keep the spatula to the metal base.

Step 10

Place a cake round or serving plate over the top and turn the chiffon cake out. it's normally served upside down.

Step 11

Combine all of the ingredients in a bowl and mix with a spoon. Do not use a whisk as it can make air bubbles. If it is too thick, add a bit more juice or water, if too thin, add a little powdered sugar to get to the right consistency.

Step 12

Pour over the cake allowing the excess to run down the side of the cake.

Step 13

To store, place under a cake dome where it will last for several days. For longer storage, freeze the cake, without the glaze, until hard. Wrap well. It will keep for several months. Thaw, uncovered at room temperature. Glaze after it is thawed.