10 to 12 ounces frozen pandan leaves, thawed
1/3 cup coconut milk
8 ounces cake flour, or 7 ounces all-purpose bleached flour plus 1 ounce cornstarch
1/2 teaspoon salt
2 teaspoons baking powder
10 1/2 ounces sugar
7 large egg yolks
1/2 cup canola or vegetable oil
1 to 2 teaspoons vanilla (optional)
8 large egg whites, at room temperature
1 teaspoon cream of tartar
Position a rack in the middle of the oven and preheat to 350F degrees. Have an ungreased round tube cake pan handy.
Use scissors to cut the pandan leaves into short pieces, no more than 1 inch long. In 2 batches, blend the cut leaves with the coconut milk (use half of the milk at a time) in a food processor until it looks like bits of grass. Pause and push it down as needed. Transfer to a thin cloth, such as a piece of muslin.
Firmly squeeze to render the opaque green liquid into a measuring cup. Discard the solids. When done with both batches, you should have about 14 tablespoons total. Add extra water, if needed to get that quantity. Or, remove some of the liquid if you have too much.
In a large bowl, whisk together the flour, salt, baking powder, and all but 1/4 cup of the sugar. In another bowl, whisk together the pandan-and-coconut liquid, egg yolks, and oil. Whisk the liquid into the dry ingredients until well blended and smooth. Taste the batter, and if you like, add the vanilla. Set aside.
Using an electric mixer on low speed, beat the egg whites for about 15 seconds to break them up and get them a bit frothy. Then sprinkle in the cream of tartar as the machine runs. Increase the speed to medium, then gradually add the sugar.
When the sugar has been added, increase the speed to high and beat the egg whites until stiff peaks start to form. Stop the machine to check.
Take about 1/4 of the egg whites, and swiftly stir with a spatula to blend and lighten the batter a bit. Now scoop the remaining egg whites onto the batter. Use cut-and-fold motions to combine the ingredients. A few thin streaks of white in the batter are okay.
Pour the batter into the pan and shake it a bit to smooth out the top. Slide the pan into the oven and bake for 55 to 60 minutes, until a bamboo skewer inserted comes out clean.
Cool the cake on a rack for 5 minutes. Meanwhile find two bowls or jars that can be used to support the can pan in an upside down position. They have to be at least as tall as the part of the tube pan that extends beyond the rim!
Without much hesitation take the pan and invert it, positioning the rim on the bowls or jars so that the pan is elevated. Let the cake cool for 1 hour, before running an icing spatula around the edges (inner and outer) and unmolding. Slice and serve.
– See more at: http://www.vietworldkitchen.com/blog/2011/06/pandan-chiffon-cake-recipe.html#sthash.4M3E97c8.dpuf