How much baking powder is needed for 3 cups of cake flour?

Here's why:

* The standard ratio for cake flour is 1 1/2 teaspoons of baking powder per 1 cup of flour.

* Since you're using 3 cups of flour, you simply multiply that ratio by 3: 1.5 teaspoons x 3 = 4.5 teaspoons

* However, it's not practical to measure out half a teaspoon, so you'll round down to 2 1/2 teaspoons.

Remember, this is just a general guideline. The exact amount of baking powder you need may vary slightly depending on the recipe and your desired texture.