Three Layer Chocolate Cake With Frosting

Ingredients

• 1 teaspoon baking soda 
• 3 oz cake flour 
• 0.8 cup cocoa powder natural style
• 12 oz t brown sugar dark packed
• 0.3 cup dutch-processed cocoa powder dark
• 3 large eggs lightly beaten at room temperature
• 1 teaspoon espresso powder instant
• 3.8 oz flour all-purpose
• 4 tablespoons cup heavy whipping cream whole as needed plus more (or use a combination of cream and milk)
• 0.5 teaspoon kosher salt 
• 1 pinch salt 
• 0.5 cup cream sour at room temperature
• 1.5 tablespoons cream sour room temperature
• 8 ounces butter unsalted at room temperature (2 sticks)
• 8 tablespoons butter unsalted softened
• 4 ounces baker's chocolate unsweetened chopped fine
• 1 teaspoon vanilla extract 
• 1.3 cups water 
• 9 oz powdered sugar sifted

Equipment

• bowl
• sauce pan
• oven
• wire rack
• blender
• stand mixer

Directions

1. Preheat oven to 350 degrees F. Grease and flour 3 8 inch round pans. If desired, line bottoms with rounds of parchment.In a saucepan, bring the water to a boil. Turn off heat and stir in chocolate, cocoa powder and instant coffee. Stir until chocolate is melted and mixture is smooth. Stir in vanilla. Set aside to cool for about 10 minutes.Meanwhile, sift together both flours, baking soda and salt.In the bowl of a stand mixer fitted with a paddle, beat the butter until creamy.
2. Add the sugar and beat on medium high for about 3 minutes, scraping sides of bowl often. Reduce mixer speed to medium low and add the eggs slowly a few tablespoons at a time. Beat just until incorporated, then beat in the sour cream.With mixer still on low, add the flour mixture and the chocolate mixture alternately, ending with the flour. Scrape sides of the bowl again and mix well but do not overbeat. Divide batter among the three pans and bake for about 23 minutes or until cakes spring back when touched. You may need to shuffle the cakes around in the oven halfway through so theyll bake evenly.
3. Let cool for 10 minutes on a wire rack, then invert and let cool completely before frosting.Frosting: To make the frosting, beat the butter until creamy. Gradually add the sugar and beat until well mixed, then add the cocoa powder and beat until mixed it should look crumbly and pasty.
4. Add the sour cream and salt and beat well, then gradually add the cream, scraping sides of the bowl, until frosting starts looking smooth and creamy. Taste and adjust sugar and cream as needed.