Combine (A) ingredients in a large bowl, mix well with a hand whisk.
Sift in plain flour, mix well and add (C)), mix well again.
In a mixing bowl, whisk egg white and lemon juice till foamy. Add sugar in batches and whisk egg white to peak form.
Fold the egg white into the flour mixture in 3 batches with a rubber spatula. Pour batter evenly into a 20cm ungreased chiffon cake pan. Gently bang the pan on the table top to release air bubbles.
Place cake pan in the pre-heated oven 170C and bake for 50-60 minutes.
When cake is done, remove from oven and turn the pan over. Remove the cake from pan after cooling.
Recipe by Anncoo Journal at https://www.anncoojournal.com/angel-food-cake/