Prep 15 mins
Cook 2 hrs
Here's a planning tip: This can be made through step 21, wrapped in plastic wrap and stored at room temperature 1 day, or cover plastic-wrapped cake with foil and freeze up to 2 weeks. Frost with Cocoa Whipped Cream up to 1 day ahead.
- 2 cups cake flour, about (not self-rising)
- 1 teaspoon baking soda
- 1⁄4 teaspoon salt
- 1⁄2 cup unsweetened cocoa powder
- 1⁄2 cup buttermilk
- 2 teaspoons vanilla extract
- 2 large eggs, at room temperature
- 1⁄2 cup unsalted butter, softened
- 1 cup granulated sugar
- 1 cup packed brown sugar
Cocoa Whipped Cream
- 1⁄2 cup sugar
- 1⁄4 cup unsweetened cocoa powder
- 1 cup heavy whipping cream
- Position rack in lower third of oven- Heat to 350 degrees.
- Grease a 13x9x2 inch baking pan with solid shortening- Dust with flour, tap out excess and line bottom with parchment or wax paper.
- Sift flour onto wax paper.
- Measure 2 cups by lightly spooning flour into a measuring cup (the nested kind), mounding it slightly (don't tap cup on countertop)- Sweep off excess flour with back of knife, put into a medium bowl, whisk in baking soda and salt.
- In a medium bowl, whisk 1/2 cup lukewarm water into the cocoa- Let cool.
- Pour buttermilk, 1/2 cup water and vanilla into a liquid cup measure.
- Crack eggs into a small bowl; whisk to mix yolks with whites.
- Beat butter in a large bowl with mixer on medium speed 30 to 45 seconds until smooth.
- On low speed, gradually beat in granulated sugar then brown sugar- Scrape down sides of bowl (mixture will appear sandy).
- Beat on medium speed 6 to 7 minutes until mixture is light in color and comes together.
- Gradually add eggs and beat, scraping bowl at least once, until fluffy and increased in volume (This, including adding eggs, should take about 1 minutes).
- Add cocoa mixture; beat just to blend.
- With a rubber spatula, stir in 1/4 the flour mixture, then 1/3 the buttermilk mixture- Repeat, alternating dry and liquid ingredients, ending with flour mixture and mixing until blended and smooth.
- Pour into prepared pan- Spread from center out, creating a slightly raised ridge around rim.
- Bake 30 to 40 minutes or until top springs back slightly when touched lightly in center, sides contract and a wooden pick inserted in center comes out clean- Cool on wire rack 10 minutes.
- Prepare frosting while waiting: Stir in 1/2 cup sugar and 1/4 cup unsweetened cocoa powder in a large bowl to blend.
- Add 1 cup heavy whipping cream; stir to combine.
- Refrigerate at least 30 minutes for sugar and cocoa to dissolve.
- Beat with mixer on high speed until stiff peaks form when beaters are lifted- Use immediately (makes 2 cups).
- Once the cake has cooled on a wire rack for 10 minutes, run a thin knife around edge of cake, place a wire rack over pan and flip both over- Remove pan and paper.
- Turn paper sticky side up, place non-sticky side on cake, cover with a rack and flip both over so cake is right side up- Cool completely.
- To assemble: Place cake in freezer 15 minutes.
- Using a serrated knife, slightly trim narrow ends.
- Cut cake crosswise in thirds.
- Place 1 third on a platter; spread with 1/3 the Cocoa Whipped Cream- Repeat with another third.
- Top with remaining layer; spread top with remaining cream.
- Refrigerate at least 30 minutes or until ready to serve.