Cocoa-Buttermilk-End-of-the-Month-Celebration Cake

I just watched the movie (500) Days of Summer, and while it was an exercise in complete and total wannebee hipster lameness, the "protagonist" wrote cards for a living. There's a scene where all of the cardwriters(?) are trying to come up with new holidays to sell more cards. If I were in that movie, I would have won an academy award for best card concept-- END OF THE MONTH CAKE DAY. To celebrate the end of the month and the start of a new one, bake a cake. And I mean CAKE. A celebration cake.
This cake is way delicious. Dorie Greenspan, aka Goddess of Baked Goods, had malt powder in her recipe, because I had no malt powder I just substituted extra powdered sugar. Relatively quick, and very simple this cake is an excercise in deliciousness.

Cocoa Buttermilk End of the Month Celebration Cake
From Baking:From My Home to Yours by Dorie Greenspan

For the Cake:
2 cups all-purpose flour
1/2 cup unsweetened cocoa powder
1/2 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
2 sticks (8 ounces) unsalted butter, at room temp
1 1/2 cups sugar
2 large eggs
2 large egg yolks
1 teaspoon pure vanilla extract
1 cup buttermilk
4 ounces bittersweet chocolate, melted and cooled

Getting ready to bake: Center a rack in oven and preheat to 350 degrees F. Butter two 9x2 inch round cake pans, dust insides with flour.

To make the cake: Whisk together flour, cocoa, baking powder, baking soda, and salt.
Working with a stand mixer in a large bowl beat the butter on medium speed until soft and creamy. Add sugar and beat for about 2 minutes, until throughly blended with the butter. Add the eggs one at a time, then the yolks one by one, beating for 1 minute after each addition and scraping down the sides and bottom of the bowl as needed. Beat in vanilla. Reduce mixer speed to low and add dry ingredients alternately with the buttermilk; add the dry ingredients in 3 portions and the buttermilk in 2 (begin and end with dry ingredients); mix only until each new batch is blended into the batter. Scrape down the bowl, and if you want, add teh melted chocolate, folding it in with a rubber spatula. Divide the batter between the cake pans.
Bake for 26 to 30 minutes, or until the cakes feel springy to the touch and start to pull away from the sides of the pans. Transfer the cakes to racks and cool for about 5 minutes before unmolding. Invert and cool to room temperature.

For the Chocolate Malt Buttercream:
6 ounces bittersweet chocolate, coarsely chopped
1/3 cup (packed) light brown sugar
1/4 cup malted milk powder
1 tablespoon unsweetened cocoa power
1/4 cup boiling water
2 sticks (8 ounces) unsalted butter, at room temp
pinch of salt
3/4 teaspoon pure vanilla extract
2 1/4 cups confectioners sugar, sifted

To make the buttercream: Melt the chocolate with halft the brown sugar in a heatproof bowl set over a saucepan of simmering water. Remove from the heat.
Whisk the malt powder and cocoa together in a small owl, pour over 3 tablespoons of the boiling water and whisk until smooth. Whisking the melted chocolate gently, gradually pour in the hot malt-cocoa mixture and stir to blend-- it should be daark, smooth and glossy.
WOrking with the stand mixer, preferably fitted with the paddle attachment, or with a hand mixer in a large bowl, beat the butter on medium speed until soft and fluffy, about 2 minutes. Add the remaining brown sugar and beat for 2 to 3 minutes more, until well blended. Beat in the slat and vanilla extract, then reduce the mixer speed to low. Scrape in the chocolate mixture and mix until smooth. Still working on low speed add the confectioners sugar. When all the sugar is in, increase mixer speed to medium and beat for a few minutes. Lower speed and add remaining tablespoon of boiling water, then increase speed and give frosting another spin. It will be light and thick enough to use immediately. If it doesn't hold shape beat more.

To assemble cake: Place one layer top side up on a cardboard round or a cake plate protected by strips of wax or parchment paper. Frost top of the layer, cover with second layer, top side down. Frost the sides and top of the cake, either smoothing teh butter cream for a sleek look or using a spatula, knife or spoon to swirl it for a more exuberant look.
Refridgerate cake for at least 1 hour to set frosting, then bring to room temp and serve. (Lies. Who can wait ONE WHOLE HOUR?)