To rise or not to rise

A good question:
Q: How do I make Self raising flour from cake flour?

A: Easy! 2 teaspoons of Baking Powder to one cup (250ml) of Cake/Plain flour.

Cake flour is used mainly for cakes and pastries as the protein molecules are finer and produce a firm crumb, whereas Self raising flour is for cakes needing an extra lift as it contains baking Powder, which has biological raising agents causing the chemical reaction in cakes when they are cooked. Plain flour with no added raising agents (such as air when sifted, yeast or Baking Powder) will result in a very flat cake.