I would suggest that you either waited too long after mixing the cake before getting it into the oven or your baking powder was over the hill. Also that appears to be a very small amount of baking soda to add to a cake containing a cup of buttermilk.
Linda C

Thanks, Linda, but the cake went into the oven immediately and the buttermilk powder had never been opened and was still within the "sell by" date.

I hate to say this, but nearly every Cooks Illustrated recipe I've ever tried has been very time-consuming, and a failure or near-failure.

I'm with you on the Cooks Illustrated recipes. They rarely become my favorites.

Lori

What about your baking powder or soda NOT the buttermilk powder? Was the bp or bs fresh as lindac asked? To me that sounds like a likely suspect...old baking power or baking soda. I can't imagine a hard cake unless maybe over mixing?

Thanks, AR girl, my eyes skipped down and I read "buttermilk" instead of "baking powder." Nevertheless, the baking powder was first opened last week. So, I believe it is fresh.

Can baking soda get old? I have no idea how long mine has been in the pantry. It isn't ancient, but it wasn't freshly opened in the last month, either.

Well that's a shame to go to all that trouble and have a flop. :(

Crummy cake, but we've been peeling the caramel icing off and eating it!

Caramel icing sounds good!!

You can tell if baking soda is fresh enough to use by mixing a little baking soda with a little vinegar. If it foams up, it's fine. Otherwise, toss it.

Lori

Nope, baking soda wasn't the problem. I got immediate, vigorous bubbling when I tested it. I think it is just a lousy recipe!

Might I suggest picking the frosting off and then slicing the cake and toasting it and call it a cookie!
I stopped getting cooks illustrated after a similar disappointment making a recipe for calzone.
Linda C

My guess is that the oil and melted butter are the culprits. Most cakes I have seen using melted butter are denser cakes such as fruit cake. I'd be tempted to try it again without the oil and with unmelted butter (add extra to account for not using the oil) using the traditional creaming method.

Well I'm going to say it was the melted butter. Last year I attempted a pound cake which called for melted butter and it produced the worst cake I've ever made in my life! I'm a fairly experienced baker and I know I did everything right. The cake turned out rubbery and with pretty much inedible. The worst part was I had made it for dinner at a friends and then I had to forbid everyone from eating it after I my DH tried the first piece. I don't think you did a thing wrong!

Tracey

I don't know a thing about the science of baking, but my money is on the buttermilk substitution. I know everyone says it's fine, but a few years back I tried powder a few times, as directed, in a T&T blueberry corncake recipe that I was making frequently at the time and had consistently bad results so I threw out the rest. I don't rememeber the brand, but it was the one that everyone here seemed familiar with.

I find CI recipes very reliable. I might not love every one and certainly not every one becomes my favorite, but I can't recall ever having a fundamental failure like this.

I almost said the melted fats were the culprit, until I read the recipe, and noticed its similarities to the reliably-classic Chiffon Cake, which also calls for lots of eggs and fats.

I have never tried any Cooks Illustrated recipes, so I can't form an opinion, but the strained seams on my jeans can attest to the years of baking I've been accused of.

I noticed a few things that might've gone wrong. The first would be the ratio of egg yolks to egg whites. Certainly the egg whites were outnumbered. In rich sponge cakes, the egg whites will, at least, equal the amount of yolks.

And the other culprit might have been found in the mixing. Incorporating peaked egg whites into a cake batter needs to be done with a light, quick, but very thorough hand.
And then put in the oven right away, before the whites have a chance to deflate, which also results in a heavy cake.

Btw, I think the suggestion of toasting the cake sounds like something I would do. You put too much effort into this recipe to toss it.

Sol

I'm not an experienced cake baker, as Dh doesn't like cake (I do, but why bake one just for me?). Anyway, I have used powdered buttermilk in recipes before, mostly for bread, and can't say I've had any problems. My only problem with it is it's hard to find. But then, I've had a hard time finding fresh buttermilk, too. If I do find it, it's in quarts or half gallons, which is way more than I can use up. Which is why I prefer powdered buttermilk when I can find it.

Good idea about toasting the cake!

Sally

I would blame the recipe for starters. Both the high number of egg yolks to whites and the melted butter/oil will make a cake dense and rubbery. I agree with Linda that the amount of baking soda for the amount of buttermilk seems low but I don't think that's the primary culprit. Sol also makes a good case for method. Beaten egg whites should be barely and quickly married to the batter and then folded in but not beaten. I use the buttermilk powder, too. I don't love the flavor in large amounts but I don't think that it is to blame for the heaviness of the final product.

Might I suggest picking the frosting off and then slicing the cake and toasting it and call it a cookie!
I stopped getting cooks illustrated after a similar disappointment making a recipe for calzone.
Linda C

What can I say...?

I think switching to 8" could is the main part of the problem. I don't have a problem with buttermilk powder or the ratio of baking soda - this recipe is somewhat similar to my recipe for waffles, which also uses melted butter. I think the batter needs to be spread out more. I would also switch to 5 yolks plus 4 whites, or 4 yolks and 5 whites and possibly omit the vegetable oil.

The area of an 9" pan is 1-1/4 times the area of an 8" pan, and so the batter gets piled too high. You could have made a couple of cupcakes to reduce the amount of batter you would pour into the 8" pans. Better yet, get Sol's recipe for Chiffon cake.

Lars

Note to self *don't use melted butter in cake recipes* :)

Thanks all. I think I'll just hunt around for a more reliable cake recipe.

Lindac, we did toast some thin slices. Not too bad. Mostly, DD is using it for "cake shakes" ... cake and almond milk in a tall glass hit with the stick blender. She says it is quite tasty.

I'm with Lars on this one. I'm an avid cake baker, and like FOAS, like CI's recipes, also find them reliable and have come to depend on them. Because it's a test kitchen, their recipes are very explicit for a reason. (They spent a whole segment on their show about why they specify a certain size pan when baking.) If they tell you to use an 8 inch pan, a 9 inch pan will change the way the cake bakes, which is why I suspect you had a problem. Another thing that helps add moisture to cakes is the addition of buttermilk, (or sour cream), and using a dried buttermilk product wouldn't have the same moisture properties IMO. (I tried to use it once, and ended up giving it to my MIL, as I didn't care for it.) If I'm baking from scratch, I would rather wait until I had all the ingredients for my recipe, instead of trying to make substitutes, which is what I'd consider a dried milk powder. That said, I always look for recipes that have buttermilk or sour cream as they make a moist cake that stays moist to the end.

I'll bet if you try this same recipe again using real buttermilk and a 9 inch cake pan, you'd get very different results.

CdL, I gathered all of the ingredients before starting. The use of powdered buttermilk was not because I had no liquid buttermilk. It was because it is recommended by CI. Here is an exerpt from what CI had to say about powdered buttermilk in a sidebar to the recipe I made: "All in all, do we recommend Saco's Buttermilk Blend as a replacement for liquid cultured buttermilk in baking? Yes."

I think the size of the cake pans may have contributed to the problems.

I had no doubt they do recommend buttermilk powder. (I'm no expert! However, I've used it before and personally didn't care for it, but neither would I sour milk with vinegar and think it particularly good. I don't always agree with ATK's recommendations, although if it's something I'm not sure about they are a good place to start. I'll freely admit Personal Preference here. I always have buttermilk on hand as it lasts a long time and there's so many things to do with it.) On the other hand bbstx, you made me look at pan sizes, as I couldn't quite remember what they said.

I'll admit I'm a geek; I always like to know the reason why. Here's what they had to say about pan sizes:

For best results when substituting baking pans, surface area, not shape, is what matters. We prepared our favorite yellow cake in two 9-inch round cake pans (the size specified in the recipe), two 8-inch square pans, and two 8-inch round pans. The 9-inch round and 8-inch square pans have the same surface area (see chart below), and the cake layers were done in the baking time specified in the recipe: 20 to 25 minutes. The cake layers baked in the smaller 8-inch round pans finished baking in about 25 minutes, but the bottom of the cake burned while we were waiting for the center of the cake to cook through. These layers were 3/8 inch thicker than the layers baked in the other pans.

Our conclusion? If you need to substitute one baking pan for another, figure out the surface area (in square inches) of the pan called for in the recipe, then find the pan in your cabinet that most closely matches the surface area of the requested pan. If you can't find an exact substitute, be aware that using slightly larger pans will result in flatter cakes and slightly reduced baking times and that using slightly smaller pans will result in taller cakes and slightly increased baking times.

Surface Area of Common Pans

Baking Pan Size Surface Area
8-inch round 50 square inches
8-inch square 64 square inches
9-inch round 64 square inches
11 inches by 7 inches 77 square inches
9-inch square 81 square inches
13 inches by 9 inches 117 square inches

On their recommendation, I also added a ruler to my kitchen tools so I'd never have to guess what size pan I was using.

and I just copied and pasted that into a word doc and will put it in my recipe file and saved another to print out to take to church.
I could have figured it out and have many times....but it's nice to have it all there in print!