Irish Car Bomb Cakes

After seeing this idea for a Saint Patrick’s Day themed cupcake on my favorite Smitten Kitchen about three years ago, I wanted to give it a try (I must say, I love what Deb does on the other side of the country.) After all, this cake includes several of my favorite things: rich desserts, Guinness, whiskey, Irish cream, buttercream, moist cake and the potential for show-stopping elegance. This year, I finally dove in and made my own barely adapted version of the Irish Car Bomb Cake, in the perfect size to share.

Guinness chocolate cakes are highly in vogue in the online baking community. After a great deal of research, I found that it’s essentially one recipe, with the only real variation coming from the scaling and exact ratios of ingredients and occasional inclusion of strong coffee or vanilla. Creativity comes in the frosting and fillings. Several recipes use a simple cream cheese frosting. Many use a basic buttercream to which Irish cream lends its classic and unique flavor. A few feature a decadent ganache flavored either of whiskey or Irish cream, but the ones that inspired me the most used a whiskey ganache and Bailey’s buttercream.

What I like best about this recipe is that the cake itself is simple to make, and the flavorings of the frosting and filling are easily added to almost any preferred recipe for buttercream or ganache. Though these recipes are not highly varied, many bakers have their own personal touch that works best for them – I like the addition of an egg white to the buttercream for the silkiness it lends to the melt-in-your-mouth texture.

While this recipe is written for ramekins to make miniature cakes, experiment with different means of baking. This recipe will yield two nine inch rounds or squares or about two dozen cupcakes. It will also produce a combination of the above, potentially yielding a dozen cupcakes, along with a modest single layer cake or several beautiful mini cakes. The ganache and buttercream can also be used interchangeably to fill or cover the cakes, making this recipe endlessly flexible for the creative baker.

To make the cake, bring the stout to a simmer with the butter. Add the cocoa powder and whisk thoroughly until the mixture is smooth and thickened slightly. Allow this to cool slightly as you sift the dry ingredients together.

In a stand mixer, beat the eggs and sour cream, and then gradually add the cocoa, stout and butter mixture. Scrape the sides of the bowl thoroughly to ensure thorough mixing. Add the dry ingredients in several batches, mixing on a low speed just until combined, scraping the sides of the bowl as needed.

Pour or spoon the batter into the prepared baking dishes. I prefer to butter cake pans and coat them in sugar to lessen the chances of sticking, though parchment cut to fit the bottom and buttered with the pan works as well. Bake the cakes until springy to the touch, with a cake tester coming out clean. Baking time will vary depending on the baking dishes used: cupcakes should be done in fifteen to twenty minutes. Ramekin cakes bake in about twenty to twenty five minutes and nine inch cakes in about thirty to thirty five. Let the cakes cool five to ten minutes before inverting onto a wire rack to cool completely.

For the buttercream, beat the butter until light and fluffy. Add the egg white and about half of the powdered sugar. Mix to incorporate and then beat on high until fluffy. Add the Irish cream and continue to beat, adding enough additional powdered sugar to make a light, fluffy buttercream with enough body to hold its shape well.

For the ganache, bring the cream to a simmer and pour over the chopped chocolate in a heat-proof bowl. Add the butter and let it sit for a couple minutes before whisking the chocolate chunks into the cream until the mixture is smooth and thick. Add the whiskey and whisk until smooth.

Chill the cakes before filling. For the ramekin cakes, slice each in half to create two three-and-a-half inch cake rounds. Fill them with the desired amount of buttercream, and very thinly frost the sides to create a smooth side. Freeze the cakes until firm, about fifteen minutes, to ensure that the warm ganache doesn’t melt the buttercream.

When the ganache is almost cooled to room temperature but still fluid, space the cakes apart on a wire rack set over a rimmed baking sheet. Working one at a time, spoon the ganache onto the cakes, allowing it to dribble down the sides. Use an offset spatula to coax the ganache to smoothly cover the whole cake – less touching and a rapid, smooth hand yield the best-looking results with ganache. After the excess has dripped from the cakes, allow them to chill until the ganache is firm.

Though my mother owned a cake decorating business when I was very young, it shames me to admit that my pastry bag piping skills are at best meek – a simple and elegant flower can be produced even by novice cake decorators with a long, narrow tear-drop shaped pastry bag tip. Start in the middle and layer a series of petal-like ruffles outwards in an organic, random, overlapping pattern until an attractive blossom forms. Practice onto the back of a spoon, into the buttercream bowl or onto a Graham cracker or saltine until the desired technique is achieved. The buttercream becomes challenging to work with as it warms, so pay attention to how soft the pastry bag feels and refrigerate it when it begins to lose body.

Transfer the cakes onto individual plates or a serving platter with an offset spatula. Gently loosen the cake and carefully lift it; gently slide it in place. Refrigerate the cakes until ready to serve, loosely covered. Before serving, allow them to sit at room temperature to soften slightly. The miniature cakes are generous portions, and the cake is so sweet and rich that they are perfect for sharing between two.

Irish Car Bomb Cakes

This cake is moist and richly flavored of chocolate, but with a twist from the black beer. Keep in mind that the filling is sweet and rich when filling the cake, but it balances beautifully with the bittersweet whisky ganache. Plan for small serving sizes!


1 cup stout (Guinness)

1 cup butter

¾ cup Dutch processed cocoa powder

2 cups all-purpose flour

2 cups sugar

1½ teaspoons baking soda

¾ teaspoons salt

2 large eggs

2/3 cup sour cream

Whisky Ganache

12 ounces bittersweet chocolate, finely chopped

1 cup heavy cream

3 tablespoons butter

1 tablespoon Irish whisky

Bailey’s Buttercream

1 ½ cups butter, at room temperature

5 to 6 cups confectioners’ sugar, sifted

1 egg white

6 tablespoons Bailey’s Irish cream

  • Preheat the oven to 350°. Generously butter and sugar ten to twelve three-and-a-half by two inch ramekins.
  • To make the cake, combine the butter and stout in a small sauce pan and bring to a simmer over medium heat. Add the cocoa powder and whisk thoroughly until smooth and slightly thickened. Set aside to cool slightly.
  • In a medium bowl, sift together the flour, sugar, baking soda and salt.
  • In the bowl of an electric mixer, beat the eggs and sour cream until smooth. Add the cocoa mixture, scraping the sides of the bowl and beating to combine.
  • Add the sifted dry ingredients in three portions, beating on a low speed just until incorporated. Divide the batter between the prepared ramekins and bake in the preheated oven until the top is springy and a toothpick inserted into the cake comes out clean, about twenty to twenty five minutes. Let cool five to ten minutes before inverting onto wire racks to cool completely. Chill the cakes.
  • Meanwhile, prepare the butter cream in the bowl of the stand mixer by beating the butter until it is light and fluffy. Add the egg white and three cups of the powdered sugar. Mix on a low speed until combined, and then beat until fluffy. Add the Irish cream, and beat thoroughly. Add enough of the remaining powdered sugar to make a fluffy, creamy frosting that holds its shape well. Set aside.
  • To make the ganache, bring the cream to a simmer in a small sauce pan. Combine this with the chocolate in a medium bowl and let sit for a couple minutes. Add the butter and whisk thoroughly until smooth. Add the whisky and stir to incorporate. Set aside.
  • Slice each chilled cake in half through the middle. Add a dollop of butter cream between the layers and lightly frost the sides to produce a smooth surface. Freeze for fifteen to twenty minutes.
  • Arrange filled cakes two to three inches apart on a wire rack set over a rimmed baking sheet. Spoon a generous dollop of ganache over the top and gently coax it to spill over the edge. Use an offset spatula to smoothly cover the whole cake in ganache. Allow excess to drip from cakes and refrigerate until the ganache is firm, thirty to forty minutes.
  • Fill a pastry bag fitted with an appropriate tip (such as number 104) about half to three quarters full with buttercream. Starting from the center, pipe the frosting into a rosette of ruffles and petals to form a loose blossom. Transfer the individual cakes to plates or a platter by gently loosening with an offset spatula and sliding onto the serving dish. Return to the refrigerator. When ready to serve, let sit at room temperature ten minutes.

Yields ten to twelve mini cakes, each appropriate to share

15. March 2012 by Matt Jackson
Categories: Dessert, Holidays | Tags: , , , , , , , , , , , , , , , , | 1 comment

One Comment

  1. I was lucky enough to be one of the people Matt shared this cake with. It is DELICIOUS! I am usually really picky about frosting (it can be too sugary a lot of the time) but this one did not disappoint. The Baileys gives it a nice smooth flavor and made it hard to stop eating. The ganache was the first thing I ate..because I couldn’t stop myself. It was soo good. I’ve had Guiness cake before but a lot of the time it just tates like a plain ol chocolate cake to me. Nothing special about it. This one was moist and delicious. I keep trying to find the appropriate words to sum up the cake but I can only think of one pharse: “DAMN it was good!” :) He’s right though..don’t try to eat it all alone. It really is meant for sharing.

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