This chocolate cake recipe makes a dark rich cake. It is frosted with a simple chocolate butter cream frosting.
Preheat oven to 350 degrees F.
Line with parchment paper, two 9-inch round cake pans and grease the parchment paper with butter. Lightly dust the pans with flour.
Combine the chopped chocolate, cocoa powder, and hot water in medium sized heatproof bowl.
Set the bowl over a saucepan filled with 1 inch of simmering water.
Stir the mixture with rubber spatula until chocolate has melted.
Add 1/2 cup sugar to the chocolate and stir for about 2 minutes until glossy.
Remove bowl from heat and set aside to cool.
In a medium size bowl stir together the flour, baking soda, and salt.
In a small bowl, combine buttermilk and vanilla.
In a large mixing bowl, using an electric mixer, beat the eggs and yolks on medium-low speed about 10 seconds until combine.
Add remaining 1 1/4 cups of sugar, and increase speed to high. Beat 2 to 3 minutes, until fluffy and lightened in color.
Add in the cooled chocolate mixture and mix about one minute on medium speed until thoroughly incorporated. Scrape down sides of bowl with rubber spatula as needed.
Add the butter 1 tablespoon at a time.
Add 1/3 of the flour mixture, mix in.
Add half of the buttermilk mixture mixing until incorporated.
Add half of remaining flour mixture, mix in.
Add all of remaining buttermilk mixture, mix in.
Scrape down sides of bowl and add remaining flour mixture.
Mix at low to medium speed until batter is thoroughly combined.
Use a spatula to scrape bottom and sides of bowl mix in.
Divide batter evenly between prepared cake pans; smooth batter to edges of pan with spatula.
Bake cakes in preheated oven 25-30 minutes or until toothpick inserted into center comes out with a few crumbs attached.
Remove and place can pans onto cooling rack for 10 minutes then invert the cakes onto the racks.
Cool the cakes completely before frosting.
Chocolate Butter Cream Frosting
Cream butter for a few minutes on medium speed, or vigorously with a fork.
Sift 3 cups confectioners' sugar and 1/2 cup cocoa into the butter bowl.
Mix on low until creamy.
Add vanilla extract, salt, and milk/cream and beat for 3 minutes. If using an electric mixer, increase speed to medium.
Notes: To thicken the consistency, add a little more sugar.
To think the consistency, add additional milk 1 tablespoon at a time.
Divide the frosting, so you have about 3/4 cup for center, 1 cup that you will put into a piping tool,
and the remaining 1 1/4 cups for frosting the top and sides of the cake.
Place one layer of cake onto a cake plate.
Spread a layer of chocolate frosting.
Place the second layer of cake onto the frosted layer.
Frost the top and side of the cake and make smooth with a spatula.
Pipe the garnish around the top edge of the cake.