Devil's Food Cake with Brown Sugar Buttercream

This devil's food cake is surprisingly light and fluffy. I made my batter into about 24 cupcakes (see Cook's Notes). They are done when a toothpick comes out with a few crumbs stuck to it. They will be rather squishy when hot. Be careful when removing if you have to take them out when they're hot (I only have one cupcake pan, so I had to in order to get the next set going). As they cool, they will firm up.

I've never actually made buttercream before, let alone using this meringue-candied sugar method. I also don't have a kitchen thermometer, which could have caused a problem. Thank God for the internet! Approximately 240˚F sugar is considered the "soft ball" stage. This means that when you drop a little of the boiling sugar into room-temperature water, it will almost immediately form a ball of sugar. Scoop it out of the water and make sure that the ball starts to flatten a little when pulled out. If it's hard and doesn't flatten, you've missed the "soft ball" stage. If the sugar kind of just falls to the bottom of the water but doesn't start to clump, keep cookin'! Don't worry about overcooking the sugar while you're testing the soft ball—240˚F is the very high side of the soft ball stage. Making this frosting was a little nerve-wracking, but it was soooooooooo worth it. This meringue-based frosting stuff is the smoothest I've ever eaten. I'm never making anything else ever again! (There are many variants of this recipe in the Gourmet Cookbook.)

Difficulty: Medium

Yeilds: 1 cake or 24 cupcakes

1 cup boiling water
3/4 cup unsweetened cocoa powder (not Dutch-process)

1/2 cup whole milk

1 teaspoon vanilla extract

2 cups all-purpose flour

1 1/4 teaspoons baking soda

1/2 teaspoon salt

2 sticks (1/2 pound) unsalted butter, softened

1 1/4 cups packed dark brown sugar

3/4 cup granulated sugar

4 large eggs

Brown Sugar Buttercream (recipe follows)

Put racks in upper and lower thirds of oven and preheat oven to 350˚F. Butter cake pans and line bottoms with rounds of parchment or wax paper. Butter paper and dust pans with flour, knocking out excess.

Whisk together boiling water and cocoa powder in a medium bowl until smooth, then whisk in milk and vanilla. Sift together flour, baking soda, and salt into another bowl.

Beat together butter and sugars in a large bowl with an electric mixer at medium speed until pale and fluffy. Add eggs one at a time, beating well after each addition. Beat in flour and cocoa mixtures alternately in 3 batches, beginning and ending with flour mixture (batter may look curdled).

Divide batter among pans and smooth tops. Place two pans in middle of oven and one pan in the bottom (do not put the top pans directly above bottom pan). Bake, switching position of pans halfway through baking, until a wooden pick or skewer inserted in center of cakes comes out clean and layers begin to pull away from sides of pans, 20 to 25 minutes.

Cool layers in pans on racks for 10 minutes, then invert onto racks, remove paper, and cool completely.

Put 1 cake layer right side up on a cake plate and spread with about 1 cup buttercream. Top with another layer, right side up, and spread with another cup buttercream. Top with remaining layer and frost top and sides of cake with remaining buttercream.

"Cook's Notes"

• The cake layers can be made up to 2 days ahead and kept, well wrapped in plastic wrap, at room temperature. They can also be frozen for up to 1 week. Thaw, still wrapped, in the refrigerator.
• The cake can be assembled up to 1 day ahead and refrigerated in a cake keeper or loosely covered with plastic wrap (use toothpicks to hold wrap away from frosting). Bring to room temperature before serving.
• The batter can also be baked in two 9-by-2-inch round cake pans for 25 to 30 minutes; in a 13-by-9-inch baking pan for 35 to 40 minutes; or in a 12-cup Bundt pan for 35 to 40 minutes. Or it can be used to make cupcakes: bake in twenty-four (1/3- or 1/2-cup) muffin cups for 20 to 25 minutes.

Brown Sugar Buttercream

3 large egg whites, left at room temperature for 30 minutes

1/8 teaspoon salt

1 cup packed dark brown sugar

1/2 cup water

1/2 teaspoon fresh lemon juice

3 sticks (3/4 pound) unsalted butter, cut into tablespoons and softened

2 teaspoons vanilla extract

Combine egg whites and salt in large bowl.

Stir together brown sugar and water in a small heavy saucepan and bring to a boil over moderately high heat, washing down sides of pan with a pastry brush dipped in cold water.

As soon as sugar reaches a boil, start beating whites: with an electric mixer at medium-high speed, beat whites until frothy, then add lemon juice and beat and medium speed until whites just hold soft peaks. (Do not beat again until sugar syrup is ready.)

Meanwhile, continue boiling sugar syrup until it reaches 238˚-242˚F on a thermometer. Immediately remove from heat and pour into a heatproof 1-cup glass measuring cup. Slowly pour hot syrup in a thin stream down side of bowl into egg whites, beating constantly at high speed. Continue to beat meringue, scraping down sides of bowl with a rubber spatula as necessary, until cool to the touch, about 6 minutes. (It's important to cool meringue properly before proceeding.)

With mixer at medium speed, add butter one piece at a time, beating well after each addition until incorporated. (If meringue is too warm and buttercream looks soupy after some of butter is added, chill bottom of bowl in a larger bowl filled with ice and cold water for a few seconds, then continue to beat in remaining butter.) Continue beating until buttercream is smooth. (Mixture may look curdled before all of butter is added, but it will come back together before beating is finished.) Add vanilla and Beat for 2 minutes more.

"Cooks Notes"

• The buttercream can be made up to 1 week ahead and refrigerated, covered. It can also be frozen in an airtight container for up to 1 month. Bring to room temperature (do not use a microwave) and beat with an electric mixture until smooth before using.