Brown Butter Hazelnut Cake
It was my birthday recently (okay, if we’re being honest it was
almost more than a month ago because I’m slow at this whole blogging thing), and I think we’ve established that to me birthdays mean one thing and one thing only: cake. So in preparation I spent a lot of time salivating over pictures of gorgeous cakes on various food blogs, but in the end it had to be Smitten Kitchen. Is anyone surprised? No. She has a recipe for a cake made with browned butter (mmm) and toasted hazelnuts (mmmm) and topped with chocolate ganache (mmmmm). It was meant to be. And the cake was everything I dreamed: light and airy from whipped egg whites, delicately flavored by the hazelnuts and brown butter, with just enough chocolate to make it a little bit rich. It was delicious.
But oh, the hazelnuts.
Those hazelnuts were the bane of my existence for the entire afternoon. Two hours of shelling because of course I don’t own a nut cracker so I had to use a garlic press (it seemed logical at the time…), and then the stupid things also have to be skinned. Searching the knowledge of the Internet turned up a couple possible methods, so I did a little experimentation. They all operate under the basic premise that heat breaks down bonds, which will make the skins easier to remove. The most commonly suggested methods are dry roasting for 10 minutes and boiling with baking soda for 3 minutes, but as (hopefully) any middle schooler worth his salt knows, this is changing way too many variables at once. I added one in-between condition: boiling for 3 minutes without baking soda. It’s not great for comparison to roasting because of the difference in time, but it will tell us whether or not the baking soda is important. Let the experiment begin!
Method 1: Dry roasting
Spread the nuts on a baking sheet and bake at 350 degrees F for 10 minutes. When you take them out of the oven, wrap them in a clean linen towel and let them steam for 3 minutes. Rub them with the towel; most of the skins should come off. Let them cool the rest of the way and rub any remaining skin off with your fingers.
Method 2: Boiling without baking soda
Heat water (3 c. per 1 c. hazelnuts) to a boil. Add the nuts and boil for 3 minutes. Pour into a strainer, let cool for 3 minutes, and rub with fingers to remove skin.
(211, 213, 216)
Method 3: Boiling with baking soda
Heat water (3 c. per 1 c. hazelnuts) to a boil. Add 4 T. baking soda per 1 c. hazelnuts, then add the nuts and boil for 3 minutes. Pour into a strainer, let cool for 3 minutes, and rub with fingers to remove skin.
(222, 225, 230, 234, 235)
And the winner is….
It depends. Boiling without baking soda was pretty much a bust, so much so that after struggling to part skin from nut on a few, I threw them back in the pot and added baking soda that time. So boiling is out.
Between boiling with baking soda and dry roasting, though, the results are not so clear. Boiling with baking soda was without a doubt the easiest way to remove the skins: the skin gets loose and flappy and you just have to rub the nuts between your hands to get it to fall right off. Unfortunately, though, the taste and texture were affected. Baking soda is a base, and bases usually taste soapy–not really something I’m after in a cake. It’s not super strong, but it was enough that I noticed it while eating the nuts by themselves. The boiling also softens the inside of the nut and weakens its crunch.
Dry roasting, on the other hand, was not quite so great at removing the skins (a few were mostly covered, and a few more had some spots), but the nuts were delicious. The texture stayed firm and crunchy, and as a bonus, you’re toasting them at the same time–which just makes them taste even better.
So it turns out the winning method depends on what’s most important to you. Boiling with baking soda is definitely the easiest way to get the skins off, but if you’re going to eat them plain or lightly adorned, I’d go with dry roasting. You keep some skin but you can’t beat the flavor. If you do boil the nuts in baking soda, make sure you toast them afterward to put the crunch back in and get the great toasty flavor.
So our experiment clearly showed that the baking soda has a big effect: boiling the nuts without it didn’t really do anything at all. And it turns out McGee agrees (whew. I wouldn’t want to contradict my main source with my admittedly slightly slapdash experiment). He says that adding base breaks down hemicellulose, a polymer made of different sugars that is present in most cell walls. It binds with pectin (which we’ve seen in pumpkin’s role in vegan baking) and cellulose, the tough fiber that makes cotton and wood strong. Together, the three make a kind of plant cement that keeps the cell walls strong and keeps the skin attached. Adding base breaks down the hemicellulose, separating the long chains into the sugars that make them up, and the cement breaks down. Voila–easy skin removal. Heat also breaks down the cement, just not quite as effectively.
I forgot to do this in my experiment, but McGee suggests putting the baking soda-boiled nuts in a dilute acid (1/2 lemon juice, 1/2 water would probably work) to neutralize any base absorbed by the nuts during boiling. This would get rid of the weird taste, although the texture might still be funny.
Brown butter hazelnut cake
In case you didn’t make it through all of the above, let me summarize: hazelnuts are divas, but this cake makes them worth it. If you value your sanity, buy them shelled (you’d think this wouldn’t be a problem, but grocery stores apparently don’t understand that sometimes I just need hazelnuts for very important cakes and then I ask the employee and he is very helpful and happy and leads me to a bag of…unshelled hazelnuts).
And thank you, of course, to Smitten Kitchen for the recipe and such enthusiasm about it that I couldn’t resist. It was everything you promised and more.
Yield: 1 10-inch cake
5 oz. (about one heaping cup) hazelnuts, with skins removed
1 c. butter
1/2 vanilla bean
1 1/3 c. powdered sugar
1/3 c. flour
5 extra-large egg whites
3 T. granulated sugar
Step one: beat the hazelnuts into submission. You can remove the skins in either of two ways (details above): boil in water with baking soda (3 c. water and 1/4 c. baking soda) for three minutes, then rub the skins off, soak in 1/2 c. lemon juice mixed with 1/2 c. water for a minute, and toast at 350 degrees F for 12-15 minutes, until they are toasty and browning. Or skip the boiling and go straight to the toasting, rubbing the skins in a towel afterward to remove the skins.
Grind the toasted hazelnuts with the powdered sugar in a food processor (or your slap chop, if you don’t happen to have a food processor large enough…) until they are fine. Add the flour, using the food processor to mix it with the nuts and sugar. Pour the mixture into a large bowl.
Cut the vanilla pod in half the short way and save one half for other baking adventures. Cut the other half the long way to split it open and expose the delicious black caviar (yes, it’s really called caviar) inside. Melt the butter in a medium saucepan. Use your knife to scrape the vanilla into the butter–make sure you get it all! Add the pod to the pan as well, and cook until the butter browns and starts to smell toasty and amazing, about 6-8 minutes. Scrape the bottom as you go to ensure equal opportunity browning. Take out the pod and let the butter cool.
Using a mixer with a whisk attachment, beat the egg whites and granulated sugar to stiff peaks, about 5 minutes at high speed. When they’re ready, the peaks should stand up when you lift the whisk. Note: I’ve done this by hand as well. It’s not very fun, but it is possible. It’s best if you have multiple people and can play pass the mixing bowl because it’s a great workout for your forearms.
Gently fold in one-third of the dry mixture into the egg whites, followed by one-third of the butter. Repeat until everything is mixed, making sure you scrape the butter pan to get the crunchy bits on the bottom. Pour the batter into a greased and/or parchment paper lined pan (my cake pans have removable bottoms, which is the best thing in the world, so I usually skip the parchment paper) and bake at 350 degrees F for 50 minutes to 1 hour. Let it cool for 30 minutes, then remove it from the pan. As you can see, mine pulled away from the edge of the pan as it cooled (probably because the protein web holding it together contracted).
4 oz. semisweet chocolate, chopped
1/4 c. heavy cream
1/2 t. instant coffee (it makes the ganache taste richer. You can also use darker chocolate and leave this out–play around with it to figure out a flavor you like)
Melt everything together over a double boiler. When the cake is cool, pour on top. Delight in your creation.