Coffee Chiffon Cake

A very Happy Happy Birthday to one of my best friends, Gracie, who is celebrating her birthday today! 

As is my tradition I made her a birthday cake to celebrate the special day, normally red velvet or chocolate.  Imagine my surprise this year when she requested something new - a coffee cake - and not the breakfast variety I initially thought, but a cake that was coffee flavored.  Hmmmm...now there's one I haven't really made before.

I knew I wanted to make something that wasn't too heavy or sweet.  Maybe this was the perfect occasion to attempt a chiffon cake.  I don't have much experience making them and have been hankering to try Cook's Illustrated's version for a while now.  

Those unfamiliar with this type of foam cake will find that it's very much like a combination of angel food cake and butter cake.  The secret to the light and airy texture is the use of vegetable oil and lots of eggs (yolks and whipped whites.)  To finish off the cake I frosted it with coffee swiss meringue buttercream.

Based on the yummy crumbs I sampled I predict Gracie will be very happy with this year's cake.

Coffee Chiffon Cake (adapted from Cook's Illustrated)

1 1/2 cups granulated sugar
1 1/3 cups cake flour
2 teaspoons baking powder
1/2 teaspoon table salt
7 large eggs, 2 left whole, 5 separated
3/4 cup strong coffee, room temperature
1/2 cup vegetable oil
1 tablespoon vanilla extract
1/2 teaspoon almond extract
1/2 teaspoon cream of tartar 

Coffee Swiss Meringue Buttercream (recipe below)

Adjust rack to lower-middle position and heat oven to 325 degrees. Whisk sugar, flour, baking powder, and salt together in large bowl (at least 4-quart size). Whisk in two whole eggs, five egg yolks (reserve whites), coffee, oil, and extracts until batter is just smooth.

Pour reserved egg whites into large bowl; beat at medium speed with electric mixer until foamy, about 1 minute. Add cream of tartar, increase speed to medium-high, then beat whites until very thick and stiff, just short of dry, 9 to 10 minutes with hand-held mixer and 5 to 7 minutes in KitchenAid or other standing mixer. With large rubber spatula, fold whites into batter, smearing in any blobs of white that resist blending with flat side of spatula. 

Pour batter into large tube pan (9-inch diameter, 16-cup capacity). Rap pan against countertop five times to rupture any large air pockets. If using two-piece pan, grasp on both sides with your hands while firmly pressing down on the tube with thumbs to keep batter from seeping underneath pan during this rapping process. Wipe off any batter that may have dripped or splashed onto inside walls of pan with paper towel.

Bake cake until wire cake tester inserted in center comes out clean, 55 to 65 minutes. Immediately turn cake upside down to cool. If pan does not have prongs around rim for elevating cake, invert pan over bottle or funnel, inserted through tube. Let cake hang until completely cold, about 2 hours.

To unmold, turn pan upright. Run frosting spatula or thin knife around pan's circumference between cake and pan wall, always pressing against the pan. Use cake tester to loosen cake from tube. For one-piece pan, bang it on counter several times, then invert over serving plate. For two-piece pan, grasp tube and lift cake out of pan. 

Frost the cooled cake with coffee swiss meringue buttercream.  [I piped leftover buttercream on the top of the cake and and placed a coffee bean in the center of each rosette.]

Coffee Swiss Meringue Buttercream (from Cook's Illustrated)

3 tablespoons instant espresso powder
3 tablespoons water (warm)
4 large eggs
1 cup granulated sugar
pinch table salt
1 pound unsalted butter (4 sticks), softened, each stick cut into quarters 

Dissolve instant espresso powder in warm water; set aside.

Combine eggs, sugar, and salt in bowl of standing mixer; place bowl over pan of simmering water. Whisking gently but constantly, heat mixture until thin and foamy and registers 160 degrees on instant-read thermometer.

Beat egg mixture on medium-high speed with whisk attachment until light, airy, and cooled to room temperature, about 5 minutes. Reduce speed to medium and add butter, one piece at a time. (After adding half the butter, buttercream may look curdled; it will smooth with additional butter.) Once all butter is added, add dissolved coffee, increase speed to high and beat 1 minute until light, fluffy, and thoroughly combined. (Buttercream can be covered and refrigerated up to 5 days.)