Guinness Chocolate Fudge Cake is a rich & chocolate-y cake with an entire cup of Guinness in the batter. The cake is topped with a whipped white chocolate Guinness Ganache frosting.
This recipe is based on a mistake. The plan was to make Guinness Brownies with a Guinness icing. As I often do when I’m developing a new recipe, I started from an existing recipe. The starting point for this recipe was my Habanero Brownies. Those brownies have great flavor and a nice fudgy texture without being super sweet or greasy.
I knew that adding Guinness to the batter would make brownies that are more cakey and less fudgy. I’ll state right here that I’m firmly in the fudgy brownie camp. No cakey brownies for me. If I want cake, I’ll make cake. If I want brownies, I’ll make brownies.
Anyway, to compensate for the extra liquid from the Guinness I increased the amount of butter and chocolate in the recipe and added a couple of egg yolks. I figured those changes would keep the batter rich enough to bake up like a brownie.
So, ok, it’s Guinness Chocolate Fudge Cake!
Well, I was wrong. While the pan was in the oven I saw that the batter was puffing up more than a brownie would. Once it was out of the oven and cooled, I sliced it open. I immediately discovered that what I had was a very moist, dense cake — or a very cakey brownie. But I really loved the flavor and didn’t want to reduce the amount of Guinness in the batter.
In the end, since I’m anti-cakey brownie and pro-fudgy cake, I decided this is a cake recipe and not a brownie recipe after all. The whipped, white chocolate Guinness ganache on top melts in your mouth and is the perfect sweet match for what I’m now calling a Guinness Chocolate Fudge Cake.
I love the way the tan ganache on top of the brown cake echos the colors of a pint of Guinness with a head of foam. Perfect!

Guinness Chocolate Fudge Cake with Guinness Ganache
Guinness Chocolate Fudge Cake is a rich & chocolate-y cake with an entire cup of Guinness in the batter. The cake is topped with a whipped white chocolate Guinness Ganache frosting.
Ingredients
- 1 1/4 cups (6 oz, 170g) all purpose flour
- 1/2 teaspoon salt
- 3/4 teaspoon baking powder
- 10 ounces (280g) bittersweet chocolate, chopped
- 8 ounces (2 sticks, 225g) unsalted butter, cut into 1" chunks
- 1 tablespoon vanilla
- 1 Cup (8 oz, 235 ml) Guinness Stout
- 3/4 cup (6 oz, 170g) granulated sugar
- 3/4 cup (6 oz, 170g) light brown sugar
- 4 eggs
- 2 yolks
Guinness Ganache
- 8oz white chocolate, chopped
- 1 oz butter
- 1/4 cup heavy cream
- 1/4 cup Guinness
Instructions
Prep the pan
- Butter a 13x9 inch baking pan
- Line the pan with either parchment or foil (see how to line the pan here)
- Preheat the oven to 325°F convection or 350°F regular
Make the batter
- Sift together the flour, salt, baking powder, set aside
- Combine the chopped chocolate and the butter in a microwave safe bowl
- Microwave for 1 minute, stir to combine
- Microwave in 30 second increments (stirring between) until all the chocolate is melted
- Stir the Guinness and vanilla into the chocolate mixture, the mix will thicken
- Add the sugars to the chocolate mixture, stir to combine
- Add the eggs and yolks and stir to combine
- Add the flour mixture and stir just until combined
- Spread the batter evenly into the prepared pan
- Bake until a toothpick inserted in the center comes out clean (25-30 minutes)
- Cool to room temperature then lift the cake out of the pan
Make the Guinness ganache
- Melt the white chocolate and butter in the microwave, stir every 30 seconds to avoid burning
- Heat the heavy cream until its very warm, but not boiling
- Add the warm cream to the ganache (it will thicken up)
- Add the Guinness to the ganache and stir until smooth
- Cool the ganache to room temperature
- Whip ganache until it lightens in color and is aerated. It should be the texture of buttercream.
- Spread the ganache evenly over the cake
- Refrigerate until the ganache is set
- Cut into 24 squares (for clean edges wipe the knife with a damp cloth between cuts)
Notes
These cake keeps for several days at room temperature.
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Kay
Wednesday 16th of March 2022
Could you use baileys Irish cream in the frosting rather than guiness?
Eileen Gray
Thursday 17th of March 2022
Yes!
Yolanda Monsivais
Wednesday 16th of March 2022
Is the Guinness room tempature?
Eileen Gray
Wednesday 16th of March 2022
Preferably, but if it's a little cool that's fine.
Andrea
Wednesday 5th of December 2018
Could this b made as a layer cake?
Eileen
Wednesday 5th of December 2018
I suppose you could bake it in two smaller pans and layer the cakes with the ganache. But it is a fairly dense cake, almost a brownie, so I might be a bit heavy.