From the Cook's Illustrated website
1. Mind your chocolate!! For the CAKE, only use baker's unsweetened chocolate.
2. Uses a standing mixer, the whisk attachment, and the beater paddle.
3. To make a sheet cake from this recipe: Instead of pouring each batter into two 9-inch round cake pans, bake each cake in a 13- by 9-inch baking dish lined with parchment paper, following the baking times and oven temperatures in the recipes. NOTE: Each sheet cake requires about five extra minutes of baking until a toothpick inserted in its center revealed a few moist crumbs: perfectly done. Let the cake cool completely before frosting it in the pan or turning it out to be frosted.
4. This recipe originally came with instructions to make ATK's chocolate frosting.
1-3/4 cups unbleached all-purpose flour (8-3/4 ounces), plus extra for dusting pans
4 oz unsweetened baker's chocolate, coarsely chopped
1/4 cup Dutch-processed cocoa (3/4 ounce)
1/2 cup hot water
1-3/4 cups sugar, divided into 1/2 cup and 1-1/4 cup (12-1/4 ounces)
1-1/2 tsp baking soda
1 tsp table salt
1 cup buttermilk
2 tsp vanilla
4 large eggs
2 large egg yolks
- For the cake
2. Cut butter into 12 pieces (12 Tbls), and allow to soften separately on a plate or on a sheet of baking paper. NOTE: Butter pieces need to be soft for mixing into batter later. If butter gets too soft, put in fridge for 2-3 min.
3. Grease two 9-inch-round by 2-inch-high cake pans with softened butter; dust pans with flour and knock out excess. Set aside.
4. In a medium heatproof bowl (better results with shallower metal bowl than with glass bowl), combine chocolate, cocoa powder, and microwaved hot water. Stir mixture until much or most of the chocolate bits are melted. (NOTE: The written directions here reflect the ATK DVD demonstration, *not* the directions in the online recipe.)
5. Rest the melting chocolate mixture on saucepan containing simmering water. Stir with rubber spatula until chocolate is melted, about 2 minutes. Once the bowl is set on the rim of the saucepan, keep it there to prevent water or steam from getting into the mixture; otherwise the chocolate will become like thick mud and can't be used. If unsure if the water is boiling or not, err on the side of too low a heat, rather than lifting the bowl to see the water.
6. With bowl still on the simmering saucepan, just before all the chocolate is completely melted, add 1/2 cup sugar to chocolate mixture. Stir until thick and glossy, 1 to 2 minutes. Remove bowl from heat and set aside to cool. (It will be several minutes before you will use it.)
7. Adjust oven rack to middle position; heat oven to 350 degrees.
8. In a medium bowl, whisk flour, baking soda, and salt. Set aside.
9. In a small bowl, combine buttermilk and vanilla. (HINT: If using a single 1-cup container of buttermilk, put the vanilla directly in the container, reclose, and shake.)
10. Separate two eggs and place just the yolks, plus the other 4 whole eggs, into the bowl of standing mixer. Have the mixer ready with whisk attachment.
11. Whisk eggs and yolks on medium-low speed until combined, about 10 seconds.
12. Add remaining 1-1/4 cups sugar, increase speed to high, and whisk 2-3 min, until fluffy and lightened in color.
13. Wipe sides of bowl and replace whisk with paddle attachment. Add cooled chocolate mixture to egg/sugar mixture and mix on medium speed 30 to 45 seconds, until thoroughly incorporated, pausing to scrape down sides of bowl with rubber spatula as needed.
14. Add softened butter one tablespoon at a time, mixing about 10 seconds after each addition.
15. Add about one-third of flour mixture followed by half of buttermilk mixture, mixing until incorporated after each addition (about 15 seconds). Repeat using half of remaining flour mixture and all of remaining buttermilk mixture (batter may appear separated).
16. Scrape down sides of bowl and add remaining flour mixture; mix at medium-low speed about 15 seconds until batter is thoroughly combined.
17. Remove bowl from mixer and with a large rubber spatula, reach to bottom of mixing bowl and fold batter once or twice to incorporate any remaining flour.
18. Divide batter evenly between prepared cake pans; smooth batter to edges of pan with spatula.
19. Bake cakes until toothpick inserted into center comes out with a few crumbs attached, 25 to 30 minutes. Cool cakes in pans 15 minutes, then invert onto wire rack. Cool cakes to room temperature before frosting, 45 to 60 minutes.