I made this cake for my husband's birthday this year. It took me most of the day. It was clearly not as easy as a mix, and I'm not sure the kids appreciated it, but I think my husband did. It makes quite a rich cake, with lots of chocolatey goodness and we couldn't come close to finishing it with our family of six. It makes a beautiful cake, though. The kind that deserves a really great cake stand, not just my Rubbermaid cake taker. (although it came in handy when taking the cake to work to let them finish it off!)
Because the recipe originates at Cook's Country (the America's Test Kitchen People) I recommend following all of the steps as outlined. They are all there for a reason.
Also, don't make the frosting until the cake is cooled already, and then frost it right away. Once frosted though, you can refrigerate it and serve it the next day. Just let it come to room temperature first so that the frosting softens and you can really taste the chocolate.
Also, note that the directions call for a stand mixer. I do not have one, and it worked out just fine.
Old-Fashioned Chocolate Layer Cake
12 Tbsp. (1 1/2 sticks) unsalted butter, very soft, plus extra for greasing pans
1 3/4 c. all-purpose flour, plus extra for dusting pans
4 oz unsweetened chocolate, coarsley chopped
1/4 c. dutch-processed cocoa powder
1/2 c. hot water
1 3/4 c. sugar
1 1/2 tsp. baking soda
1 tsp. table salt
1 c. buttermilk
2 tsp. vanilla extract
4 large eggs, plus 2 large egg yolks
1. Adjust oven rack to middle position; heat to 350 degrees. Grease two 9-inch round by 2 inch high cake pans with butter; dust pans with flour and knock out excess. (or line with parchment paper)
2. Combine chocolate, cocoa powder, and hot water in medium heatproof bowl; set bowl over saucepan containing 1 inch of simmering water and stir with rubber spatula until chocolate ins melted, about 2 minutes. Add 1/2 cup sugar to chocolate and stir until glossy, 1-2 minutes. Remove bowl from heat and set aside to cool.
3. Whisk flour, baking soda, and salt in medium bowl.
4. Combine buttermilk and vanilla in small bowl.
5. In bowl of stand mixer fitted with whisk attachment, whisk eggs and yolks on medium-low speed until combined, about 10 seconds. Add remaining 1 1/4 C sugar, increase speed to high, and whis until fluffy and lightened in color, 2-3 minutes.
6. Replace whisk with paddle attachment. Add cooled chocolate mixture to egg/sugar mixture and mix on medium speed until thoroughly incorporated, 30-45 seconds, pausing to scrape down sides of bowl with rubber spatula as needed.
7. Add softened butter 1 tablespoon at a time, mixing about 10 seconds after each addition.
8. Add about 1/3 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.) Scrape down sides of bowl and add remaining flour mixture; mix at medium low speed until batter is thoroughly combined, about 15 seconds.
9. Remove bowl from mixer and fold batter once or twice with rubber spatula to incorporate any remaining flour. Divide batter evenly between prepared cake pans; smooth batter to edges of pan with spatula.
10. Bake cakes until toothpick inserted into center comes out with a few crumbs attached, 25-30minutes. Cool cakes in pans 15 minutes, then invert onto wire rack. Cool cakes to room temperature before frosting, 45-60 minutes
Old-Fashioned Chocolate Frosting
16 oz. semisweet chocolate, finely chopped
8 Tbsp. (1 stick) unsalted butter
1/3 cup granulated sugar
2 Tbsp. corn syrup
2 tsp. vanilla extract
1/4 tsp. table salt
1 1/4 c. cold heavy cream
1. Melt Chocolate in heatproof bowl set over a saucepan containing 1 inch of barely simmering water, stirring occasionally until smooth. Remove from heat and set aside.
2. Meanwhile, heat butter in small saucepan over medium-low heat until melted. Increase heat to medium; add sugar, corn syrup, vanilla, and salt and stir with heatproof rubber spatula until sugar is dissolved, 4-5 minutes. Add melted chocolate, butter mixture, and cream to clean bowl of stand mixer and stir to thoroughly combine.
3. Place mixer bowl over ice bath and stir mixture constantly with rubber spatula until frosting is thick and just beginning to harden against sides of bowl, 1-2 minutes (frosting should be 70 degrees).
4. Place bowl on stand mixer fitted with paddle attachment and beat on medium-high speed until frosting is light and fluffy, 1-2 minutes. Stir with rubber spatula until completely smooth.
*If you find after beating, your frosting is still too soft for your liking, try chilling in the fridge until it sets up a little more.