Help! Lookin for a fluffy yellow (cup)cake recipe!

A very close friend, E., is getting married in 10 days. I'm in charge of cooking most of the food and baking the wedding cupcakes. *gulp* Luckily for me, someone with no catering experience whatsoever, the wedding is small so I won’t be cooking for tons of people for the first time, when the most I’ve cooked for is a grand total of five. And don’t worry, she knows this. I would be a craptastic friend if I volunteered for this job and said “by the way...” a few days before the wedding.

I'm trying to keep my cool for as long as possible and not flip out-verrryyyy important at this point. I finished testing all of the food last weekend (thank goodness for the 3 day weekend) and finished the yellow cake last night (there will be both chocolate and yellow cake). At least I thought I finished it. First attempt went in the compost bin because I did my math wrong, sad realization that mental math is not like riding a bike. Major fail. With the second attempt, the flavor is good, but the texture didn't meet my standards. Finals are T minus 5 days and as much as I love experimenting with recipes, I’m obviously running out of time! So dear readers, I’m going to do some thinking out loud, or rather, on this blog and please let me know what you think!

Here’s the recipe I used last night, which I adapted from a Cook’s Illustrated yellow cupcake recipe. I really respect Cook’s Illustrated, they usually never fail me so their recipe could be solid and the texture could have been compromised by the changes I made. I hate to be that person that rags on a perfectly good recipe even though I made x, y, and z changes.

(Almond) Yellow Cupcake
1 1/2 C all purpose flour
1 1/2 tsp baking powder
6 Tbsp unsalted butter
2 Tbsp canola or vegetable oil
1/2 C granulated sugar
2 large eggs
1/2 C buttermilk
1/4 tsp salt
1 1/2 tsp almond extract
1 1/2 tsp amaretto

My Adaptations:
- Original recipe called for 8 Tbsp butter, but I switched 2 Tbsp of that with 2 Tbsp of oil because I read somewhere that oil will make cakes taste moister at slightly chilled or room temp? Not sure how true this is.
- Decreased the sugar from 1 C (way too sweet) to 1/2 C
- Subbed 1/2 C sour cream for 1/2 C buttermilk
- Added almond extract and amaretto and took out vanilla extract

General idea: cream butter and sugar, add an egg at a time, beat throrougly, add oil and buttermilk. Sift in dry ingredients, and fold gently. Bake at 350F for 20 – 24 minutes.
The problem is the cake I made with all purpose flour turned out like a pound cake, which is good for breakfast, bad for wedding cake, or wedding cupcake in this case. I hate to say this, but boxed cake mix had a better, cakey texture. *hangs head in shame*

One thing I tried to avoid from the beginning is cake flour. Don’t get me wrong, I heart cake flour, it certainly makes cakes magical (called cake flour for a reason!) but it’s also more expensive compared to all-purpose flour. E. and I are trying to keep costs as low as possible.

Right now I have a few options:
- Mix of all purpose flour + cornstarch: I found a recipe in my Martha Stewart book that calls for 1 cup of flour and 1/4 cup of cornstarch (6 eggs beaten to ribbon stage, yadda yadda...).
- Another option is to mix parts all purpose flour and cake flour (again saw a few recipes in Martha Stewart’s book that did that).
- And the third option, one I have been trying to avoid, is to just use all cake flour.

Comments?

Also:
- Should I be using milk instead of buttermilk? I always thought buttermilk was superior and we rarely have milk in the house because neither Steven nor I drink it, but I'm having a hard time finding a reliable fluffy, buttermilk, yellow cake recipe. Dorie's party cake calls for buttermilk, but that's a white cake with cake flour (see cake flour above).
- Is it redundant to use both almond extract and amaretto? I had both so I just used both but I wasn’t sure if there was a taste difference or if it’s better to use one or the other.
- If I do a Genoise style cake, then I'll have to use oil, or melted butter, or a combo of both. I usually learn towards a combo of both for flavor and moistness.

What do you think? Any suggestions?