“Is that it?”
My son was concerned about the minimal ingredients I had placed on the table to use for our baking project.
Butter, chocolate, sugar, eggs. Do you ever really need more than that?
I pointed to the photo of a Chocolate Cloud Cake.
All concerns went right out the window.
We made sure the oven was heating and cut out a circle of parchment for the bottom of our cake pan.
The next step was to separate the egg yolks from the whites.
“Does anyone remember what ‘leaven’ means?”
I could see the wheels turning. And finally…
“To put air into something?”
“Yeah, kinda! It means to lighten something. Like when we lightened our pizza dough with yeast. Or a cake with baking powder and/or baking soda. What else? What about our cream puffs? What did we use to leaven those?”
“Yep, we added eggs, which in the hot hot oven, created the steam that provided lift to our cream puff dough. So we’ve used yeast, chemical reactions, steam, and now…foam.”
They had separated eggs once before, and needed little encouragement to jump in again.
I recommended that they crack the eggs on the table instead of the side of the bowl, so that any wayward shells would land on the table instead of in their egg whites.
Each kid separated their egg over a small bowl and then combined that white with the rest of the whites needed for the recipe, thus avoiding ruining a whole batch of egg whites with one broken yolk.
“Those are what we call goldfish. We want to keep those bits of yolk out of the whites.”
Fat, as in the case of the egg yolks, would keep our egg whites from foaming. For this reason, we would also make sure our whisks were very clean and would avoid using plastic bowls.
It was a good thing we had plenty of eggs on hand.
But back to this foam-as-leavening idea.
I explained that egg whites are mostly water, 90% to be exact.
“Can we make a foam with just water?”
They each tried whisking a bowl of plain water. We got some bubbles, but as expected, no foam.
Then we tried whisking one egg white.
That was more successful.
So besides water, what was in an egg white that could create a foam? We looked at it at and agreed that it was definitely thicker than water. Vocabulary word for the day: viscous.
I pulled out some bits of string and coiled them up to represent the remaining 10% of an egg white: protein.
“So these protein molecules are usually all wound up. When you guys whisk the egg white, the proteins unfold. One end likes the water, the other likes the air; they continue to open as they are exposed to the air you are incorporating with that whisk, and they trap it like so…”
“But they also like to stick to each other. So you end up with this network of many little bubbles. The more you whip, the stronger the network gets…to a point.”
We continued whipping by hand so that they could see the egg white go through the different stages.
At soft peak the whites will just start to hold shape, but will melt back into themselves after a second…
At medium peak or firm peak, the whites will form more distinct ridges but the tip will fold back onto itself. I like to think of a soft serve ice cream cone…
And at stiff peak the point will stand up proudly…
The trickiest part to whipping egg whites is taking them to the correct stage; too little whipping results in poor volume or collapse of the foam, while too much looks…
grainy, curdled, not smooth. The whites take on a dry appearance as the network gets tightened up so much that the water is essentially squeezed out.
Now that we were clear on the different stages of whipped egg whites, we could start mixing our cake.
Chopped chocolate was gently melted in a bowl set in a pan of barely simmering water.
We added soft butter to the chocolate and…
Well, just trust me that we mixed in the butter.
The kids whisked the whole eggs and yolks together with half of the sugar…
and added the chocolate and butter mixture.
They were pretty much ready to eat it as is, but I convinced them that the cake would be so. much. better.
The kids had had enough whipping by hand, so we chose to use the mixer to make our meringue. We waited until the egg whites were foamy, then began slowly adding the sugar.
Once it had thickened and began showing streaky paths from the beater, we pulled the attachment off to check…
Not quite ready yet. Back on for a sec…
They were tickled that, once whipped to a stiff peak, we could turn the whole bowl of egg whites upside down.
I lightened the chocolate mixture by folding in about a quarter of the meringue. They reminded each other how to fold as they took turns mixing in the rest.
The batter went into our parchment-lined pan and I slid it into the oven.
Like sharks I tell you. Sharks.
About 35 minutes later we had our chocolate cloud.
Ahh, but we had to wait for it to cool!
We used the time to whip up another cloud, this time with very cold cream, a pinch of sugar, and a splash of vanilla.
I explained that the stages of whipping cream were similar to those when whipping egg whites.
Me: “What do you think we would get if we over whipped this cream?”
Yep. Still delicious, but not what we wanted to top our cake.
After it had cooled a bit, the middle of the cake had sunk in just enough to leave us with the perfect place to cradle some cream.
A little white cloud of cream on top of slightly warm chocolate. Best thing ever.
Chocolate Cloud Cake adapted slightly from Richard Sax’s Classic Home Desserts
Makes one 8-inch single-layer cake; serves 8 to 12
8 oz best-quality bittersweet or semisweet chocolate, coarsely chopped (we used 72%)
1/2 c (1 stick) unsalted butter, softened
6 large eggs at room temperature: 2 whole, 4 separated
1 cup sugar
1/4 tsp fine sea salt
1 tsp pure vanilla extract
Whipped Cream Topping
1 1/2 cups heavy cream, well chilled
sugar to taste
1 tsp pure vanilla extract
Preheat the oven to 350 degrees F. Line the bottom of an 8-inch springform pan with a round of parchment paper; do not butter the pan. Melt the chocolate in a bowl set in a pan of barely simmering water. Remove from heat and whisk in the butter until melted; set aside.
In a bowl, whisk the 2 whole eggs and the 4 egg yolks with 1/2 cup of the sugar just until blended. Whisk in the salt and vanilla. Whisk in the warm chocolate mixture.
Using a standing mixer with the whip attachment, or in a bowl with an electric mixer, beat the 4 egg whites until foamy. Gradually add the remaining 1/2 cup sugar and beat until the whites form firm to stiff but not dry peaks. Fold about 1/4 of the meringue into the chocolate mixture to lighten it; gently fold in the remaining whites. Pour the batter into the pan and smooth the top.
Bake until the top of the cake is puffed and cracked and the center is no longer wobbly, about 35 – 40 minutes. Do not overbake.
Cool the cake in the pan on a wire rack; it will sink as it cools forming a crater with high sides.
At serving time whip the cream with the sugar and vanilla until not quite stiff. Run the tip of a knife around the edges of the cake and carefully remove the sides of the pan. You can choose to fill the crater of the cake with the whipped cream, pushing it gently to the edges; it looks very pretty that way. Or, if you are fighting off a crowd of impatient children, cut it into slices and top each piece with cream as it is running by.