Secret Ingredient Chocolate Cake with Luscious Cocoa-French Buttercream

I have an incredibly long to-do list/bucket list of recipes that I absolutely have to make right now. Like any to-do list however, no matter how much you hope to work through the litany of fun things to bake, this Secret Ingredient Chocolate Cake has surprisingly fallen by the wayside. I’ve always reserved this recipe to make on St. Patrick’s Day because the secret ingredient is…drumroll please…Guinness! Unfortunately, St. Patrick’s Day came and went and I still had not made this cake. However, the photo in Bernice Baran’s Frosted looks so utterly delicious that I couldn’t wait any longer and started measuring out flour and cocoa powder. After swirling the last bit of French Buttercream on top of the cake, I cut myself a slice and it was absolutely the most delicious chocolate cake and frosting that I have ever tasted. So I got to thinking- given the delicious flavor and moistness that Guinness lends to chocolate cake, it is a wonder that we only use this secret ingredient once a year on St. Patrick’s Day. And to top it all off, this chocolate buttercream is legitimately the best frosting I have ever made. This dessert is ideal for everyday snacking as well as an impressive dessert for special occasions. 

Secret Ingredient Chocolate Cake with Luscious Cocoa-French Buttercream

Who says Guinness is just for St. Patrick's Day? This moist and flavorful chocolate cake makes use of Guinness to add a distinct flavor and delicate crumb. Combined with cocoa-flavored French buttercream, this cake is perfect for year round occasions!

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Prep Time 30 minutes mins

Cook Time 40 minutes mins

Total Time 2 hours hrs

Servings: 12

Course: Dessert

Cuisine: American, French, Irish

Ingredients Method

Ingredients

  

For the Chocolate Cake:

• 1 1/2 cups all-purpose flour
• 1 cup granulated sugar
• 1 cup packed light brown sugar
• 1/2 cup unsweetened cocoa powder I use Valrhona
• 1 teaspoon baking powder
• 1 teaspoon baking soda
• 1/2 teaspoon salt
• 2 eggs room temperature
• 1/2 cup vegetable oil
• 3/4 cup buttermilk room temperature
• 1 1/4 cups Guinness extra stout room temperature
• 1 teaspoon vanilla extract

1 Recipe Cocoa French Buttercream- below

Method

 

1. Preheat oven to 350 degrees and butter and flour/ or parchment a 9×13 inch rectangular cake pan.
2. In a medium bowl, whisk together the flour, sugars, cocoa powder, baking powder, baking soda, and salt. In a separate bowl, whisk together the eggs, vegetable oil, buttermilk, Guinness, and vanilla. Fold the dry ingredients into the wet ingredients gently and just until combined. Do not over-stir.
3. Pour the batter into the prepared cake pan and bake for 35 to 40 minutes until a toothpick inserted into the center of the cake comes out clean. Allow the cake to cool for 30 minutes before turning out onto serving dish. Allow the cake to cool completely before topping with buttercream.

Cocoa-flavored French Buttercream

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Prep Time 30 minutes mins

Total Time 30 minutes mins

Course: Dessert

Cuisine: French

Ingredients Method

Ingredients

  

• 4 large egg yolks room temperature (reserve whites for another use)
• 1/4 cup water
• 1 cup granulated sugar
• 1 cup unsalted butter leave out the night before so it is very soft
• Pinch of salt
• 1/4 cup cocoa powder
• 1 teaspoon vanilla bean paste or extract

Method

 

1. Place the egg yolks in the bowl of a stand mixer with the paddle attachment and beat on medium high speed for 3 to 5 minutes until fluffy and pale yellow.
2. In a small saucepan set over medium heat, stir together the water and sugar. Cook until mixture becomes a clear syrup and the temperature reaches 240 degrees F (115 degrees C). After the initial stirring together of water and sugar, do not stir again while the mixture is cooking. Remove the syrup from the heat.
3. Turn the mixer to medium speed and pour the syrup into the bowl in a slow stream. Then, turn the mixer on high speed, and beat until the mixture is fully cooled, about 10 minutes. It is very important to make sure the mixture has cooled before moving onto the next step. It may take longer than 10 minutes.
4. Lower the mixer speed to medium and slowly add the butter, 2 tablespoons at a time, allowing each new addition of butter to incorporate into the mixture before adding more. Once all of the butter has been incorporated. Beat on high speed for 2-3 minutes, until the mixture emulsifies into a smooth and creamy buttercream. Don’t worry if it looks curdled before it has emulsified. It will come together.
5. Sift the cocoa powder and add the salt and vanilla bean paste into the buttercream. Mix just until fully combined. Spread the buttercream on top of the cake, slice, and serve. The cake is most delicious the day that it is made but can also be stored in the refrigerator for 3 days.