Ask Kemp: Chocolate Angel Food Cake and Cheesecake

by Kemp Minifie

Kemp Minifie/EpicuriousHow can it be May already? April was a busy month with some good questions. One in particular weighed on my conscience. There's nothing worse than following a recipe and ending up with extreme disappointment--particularly when the recipe involves chocolate, one of the great salves to the soul.

Q: On Twitter, @SmallDeluxe asks: "Made diabetes friendly cake that had blah taste & texture of a tennis shoe. Did I overbeat my egg whites or was the recipe doomed?"

Kemp: In order to answer the question fairly, I needed to see the recipe and @SmallDeluxe kindly tweeted a photograph of it. Right off the bat, the recipe looked potentially problematic. It resembled a chocolate angel food cake recipe except that it called for far fewer egg whites (only five compared to the standard 12), and no corresponding reduction in flour.

In addition, it used less sugar per white (1.6 tablespoons per white versus the more normal 2 tablespoons per white), which isn't surprising for a diabetic-friendly baked good, but for an angel food-style batter, it set off alarm bells in my head because sugar is crucial in helping to stabilize beaten egg whites, while also adding moisture and tenderness to the cake. The whites were also lacking another stabilizer: an acid such as cream of tartar or lemon juice.

Add to this mounting list of issues the fact that the type of cocoa wasn't specified. Even though most of the cocoa butter is removed from unsweetened cocoa, some cocoas contain more fat than others. And nothing deflates beaten egg whites faster than fat. Hershey's contains .5 grams of fat per tablespoon while Ghirardelli triples that to 1.5 grams per tablespoon. I ran into this same cocoa problem when making meringue mushrooms for a Yule log cake for Gourmet.com.

The final coup was the pound of Bing cherries that were supposed to be halved, pitted, and sprinkled across the top of the batter. That's a lot of weight to add to a delicate batter. With cherries out of season, @SmallDeluxe had substituted raspberries.

To confirm my suspicions, I dutifully followed the recipe as written, but used only 1/2 pound raspberries--I couldn't get more on the batter--and sure enough, my cake turned out flat and tough, no more than 1-inch high (see photo at right). Don't beat yourself up, @SmallDeluxe. It's the recipe, not you!

I didn't want to leave @SmallDeluxe without a really good chocolate angel food cake, so I fiddled with the recipe in my home kitchen and came up with one that maintains the same ratio of sugar to egg whites--to keep it diabetic-friendly--but produces a higher, more spectacular cake that's light, moist, and tender with a satisfying hit of chocolate. This is a cake everyone will enjoy, whether you're diabetic or not (diabetics should opt for a thinner slice).

Chocolate Raspberry Angel Food Cake (see top of page)

1 cup granulated sugar, divided
2/3 cup unsweetened Hershey's cocoa
1/2 cup sifted cake flour (not self-rising; sift before measuring)
1/2 teaspoon salt
10 large egg whites
1 teaspoon cream of tartar
2 teaspoons vanilla extract
8 ounces raspberries (about 1 1/3 cups)
confectioners' sugar for dusting (optional)

Equipment: a 9-inch springform pan (at least 2 3/4-inches deep)

Preheat the oven to 350°F with the rack in the middle. Line the bottom of the springform pan with a round of parchment paper, anchoring it to the pan with a tiny smear of butter in the center.

Sift 1/2 cup sugar with the cocoa, the cake flour, and the salt onto a sheet of wax paper.

In a large bowl with an electric mixer at medium-high speed, beat the egg whites with the cream of tartar until the foam just holds a soft shape. Gradually add the remaining 1/2 cup sugar, beating, along with the vanilla, and continue to beat just until the meringue barely holds soft peaks (keep it loose; don't go all the way to stiff peaks).

Sift the cocoa mixture over the meringue and with a large whisk fold it into the meringue gently but thoroughly.

Gently transfer the batter with a rubber spatula to the ungreased springform pan, spreading it evenly and smoothing the top, and scatter the raspberries over the top. (The batter will almost fill the pan. For safekeeping put a sheet of foil on the bottom of the oven to catch any overflow from the cake pan, but I made the cake twice and it never spilled over.)

Bake the cake until a wooden skewer inserted in the center comes out clean, about 40 minutes (the cake will rise above the pan, but it doesn't spill over). Let the cake cool completely in the pan on a rack.

Run a thin knife around the edge to free the cake from the side of the pan before removing the side of the springform pan. Dust the top of the cake with confectioners sugar, if desired.

Q: @kathyrwalsh asks: How do you avoid cracks when baking a cheesecake?

Kemp: I learned this trick from watching a Alice Medrich on a television show. First off, test the doneness of your cheesecake by giving the pan a gentle shake. If a wide swath of the edge is set but the filling trembles or wobbles a bit in the center, it's done. The cheesecake will continue to cook and set as it cools. Sticking a knife in the center to test for doneness will surely get a crack going.

Next comes the most important part: When you remove the cake from the oven, immediately run a thin knife around the edge of the pan to free the hot cake from the pan. The cake will have puffed in the oven, but it will sink slightly as it cools. As long as the cake isn't stuck to the side of the pan, it will deflate slightly towards the center as it cools. If the cake isn't freed from the edge, it will crack during this cooling period.

Keep the questions coming, folks. I'm eager to help you! Tweet me @AskKemp or leave a comment.

Photo: Kemp Minifie