Please remember not to grease your chiffon tube pan and do not use pan that has a non-stick coating. Your chiffon cake will not rise well. The cake needs to cling to the pan to rise tall
Prepare cake batter:
Separate the egg whites from the yolks and then let them come to a room temperature
Preheat oven at 330 F (165 C). If you have a convection oven, I suggest lowering the temperature by 25 F (15 C). Put the softened cream cheese and sugar in a mixing bowl. Cream until they are creamy and thick, about 1 minute or 2 on a high speed. Add yolks and use a balloon whisk to mix. Add milk, sugar, and oil and whisk to mix. Sift in the flour and salt and whisk again to combine. Set aside
Whip the meringue:
Whip the egg whites using a whisk attachment until they are foamy over medium speed, then add the acid (vinegar or lemon juice) and whisk for another minute. Gradually add the sugar, in 3 batches. Once all the sugar is in, increase the speed and whip until the meringue reaches stiff but with a slight bent on the tip when you lift it up. Stop whipping
Fold meringue into the batter:
Take 1/3 of the meringue and mix it with the batter using a balloon whisk. Use a cut down and fold over motion until they are mixed. Continue with the next two 1/3 and fold using a balloon whisk. Then finish folding using a rubber spatula to make sure we get all the batter at the bottom of the bowl too. Use the same cut down and fold over motion. You shouldn't see anymore white meringue. Work gently but fast so you won't deflate too much air. The volume of the batter should be 3 to 4 times more now
Bake:
Pour the cake batter slowly and from a good height. This helps to pop any large bubbles. Use a bamboo skewer or a chopstick and run a zigzag motion through the batter to pop any bubbles inside the batter. Tap the pan on the counter 3-4 times to pop any extra bubbles
Put the pan on the middle rack and bake for 40-45 minutes at 330 F (165 C). Then lower your temperature to 300 F (150 C) and bake for another 5-10 minutes or until the cake tester comes out clean. When you touch the surface it should spring back. It's "safer" to overbake chiffon cake a bit then to underbake. When you underbake, the cake will collapse when you take it out from the oven
Cool down:
Drop the cake pan on the counter 2-3 times to minimize shrinkage and then immediately turn over to let it cool down upside down for at least 2 hours or longer. The cake will shrink a little bit and that's normal
Once it's cool down completely, use a palette knife to run through the edge and the outer center of the tube to help release the cake. Gently push the base to lift the cake out. Use a palette knife again to run through the base of the pan and then carefully release the cake.
Notes
Recipe adjustment for different tube size:
For 6 inch tube: use 3 eggs and multiply 0.75 the rest of the ingredients. Bake for 35-40 minutes , then lower temperature to 300 F (150 C) for 5-10 minutes
For 8 inch tube: use 5 eggs and multiply 1.25 the rest of the ingredients. Bake for 45-50 minutes, then lower temperature to 300 F (150 C) for 5-10 minutes
For 9 inch tube: use 6 eggs and multiply 1.5 the rest of the ingredients. Bake for 50-55 minutes, then lower temperature to 300 F (150 C) for 10-15 minutes
For 10 inch tube: use 8 eggs and multiply 2 the rest of the ingredients. Bake for 55 minutes to one hour, then lower temperature to 300 F (150 C) for 10-15 minutes