I've heard that Cake and Pastry Flour is better for making cakes... is there ever an instance when All-Purpose flour would be better choice though. Is there a certain type of cake that's better made with All-Purpose? What's the difference anyway?

The reason I'm asking is because I bought a cake cookbook today and the recipes look excellent, BUT all the recipes are made with all-purpose flour.

Generally cake/pastry flour is superior to AP flour when making cakes, since the lower protein content of the former leads to lighter cakes.

AP flour is basically bread flour and cake flour mixed together, I don't think I've ever seen a cake or bread recipe where AP flour would give a superior result to cake flour or bread flour.

I would recommend trying to sub out cake flour (use 2 cups + 2 tbsp of cake flour for 2 cups of AP flour) to see how it goes.

http://bakingbites.com/2007/05/subbing-all-purpose-flour-for-cake-flour/

Thanks Jason, I'll try that.
Another question came up when I was looking through these recipes too... what's the difference between using baking powder or baking soda? I found two recipes that are so similar (same ingredients) except that one uses the soda and one uses the powder.

Baking soda works as a leavener by combining with other acidic ingredients in the recipe (for example, vinegar), while baking powder contains both baking soda and an acidic ingredient (like cream of tartar) and can be used in recipes without other acidic ingredients.

http://culinaryarts.about.com/od/bakingdesserts/a/Baking-Soda-And-Baking-Powder.htm

Thanks so much for your help!