Hiya Homecook.  First of all, what type of cake are you trying to better?  Can't say I've ever used a cake mix in my life.  Tell us the type of cake and we can take it from there.

If you want a really light and fluffy cake then why not try making a sponge cake?
The thing is that with a sponge you do have to make sure the egg mix triples in size so an electric beater of some kind is needed.

http://www.taste.com.au/recipes/9598/basic+sponge+cake

Hi homecook,

I have a recipe that you might like - it really depends on the flour you use. I use White Wings gluten free flour which is rice flour based so is very light, fluffy and really good with any add-ins (chocolate chips, apple & cinnamon etc):

1 cup sugar
1 cup butter
1 cup flour
3 large eggs

Method:
Cream butter and sugar.
Add one egg at a time until totally combined.
Add flour and mix on low until all flour is incorporated.

Makes great cupcakes with apple pieces in the middle and cinnamon & sugar dusted on top. Great by itself too.

It's probably just finer ground flour and more sugar that make packet cakes so light.

Thanks Ms. Pablo for your answer.  it makes the most sense.  I usually do make homemade just because I like make everything possible from scratch.  This is just a conundrum that has puzzled me for a very long time.  And once in a while, depending on the result I'm trying to achieve,  I end up resorting to the dreaded processed cake mix.