A rich chocolate Guinness cake is one of those classic Irish bakes that feels luxurious but is super simple to make. The stout gives the sponge a deep cocoa note and a gentle warmth that balances the sweetness beautifully.
As it bakes, the kitchen fills with a mellow chocolate aroma that hints at the moist, tender crumb waiting inside.
This is the kind of cake you pull out for gatherings, St.Patrick’s Day parties, birthdays or any day you want something indulgent and chocolatey!
It’s straightforward to make, and most of the work happens in one bowl.
The creamy white chocolate frosting adds a smooth, lightly sweet finish that pairs perfectly with the dark, velvety sponge.
Ingredients
For the sponge
300 g butter, plus extra for greasing
150 ml Guinness
250 g plain flour
2 teaspoons baking soda
100 g cocoa powder
375 g caster sugar
3 large eggs
1 tablespoon vanilla extract
150 ml sour cream
For the frosting
200 g white chocolate
125 g butter, room temperature
225 g cream cheese
225 g icing sugar, sifted
How To Make Irish Guinness Cake
Preheat and prepare the tin
Preheat the oven to 180 C or 350 F. Grease a 23 cm (9 inch tin) and line the base with parchment paper – this will help the cake release cleanly once cooled.
Set the prepared tin aside.
Melt the butter with the cocoa and stout
Place the butter in a small saucepan and warm gently until fully melted.
Whisk in the cocoa powder until smooth, then pour in the Guinness.
The mixture will look glossy and dark, almost like a loose chocolate sauce.
Take it off the heat and let it cool slightly so it does not scramble the eggs later.
Combine the dry ingredients
In a large mixing bowl stir together the flour, baking soda and caster sugar.
Break up any small lumps with the back of a spoon.
Creating this even base helps the batter come together smoothly.
Bring the batter together
Make a well in the dry ingredients and pour in the warm cocoa & stout mixture.
Add the eggs, vanilla and sour cream.
Stir until the batter is completely combined and silky.
The texture should be thick but pourable.
Note: Small bubbles across the surface show the baking soda has activated, which is normal.
Bake until the sponge is firm and cooked through
Pour the batter into the prepared tin and smooth the top.
Bake for about 1 hour, or until a skewer inserted into the centre comes out clean.
The surface should feel springy and firm.
Allow the cake to cool in the tin for 15 minutes before lifting it onto a rack to cool completely.
Melt the chocolate for the frosting
Place the white chocolate in a heatproof bowl and set it over a small saucepan of gently simmering water.
Let it melt slowly, stirring occasionally.
Remove the bowl and let the chocolate cool for 10 minutes so it folds easily into the frosting.
Whip the frosting until smooth and creamy
Beat the butter and cream cheese together until soft and fluffy.
Mix in the cooled white chocolate.
Sift in the icing sugar a little at a time, beating until the frosting becomes smooth and spreadable.
The texture should be creamy and hold soft peaks.
Frost the cooled cake
Place the completely cooled sponge on a stand or plate.
Spread the frosting across the top in smooth, generous swirls.
The contrast between the dark sponge and pale frosting gives the cake its signature look.
Variations
Chocolate chip frosting
Fold a handful of finely chopped dark chocolate into the frosting. This adds tiny flecks that melt slightly as you spread, giving a lovely texture.
Extra rich stout flavour
Warm an additional splash of Guinness and whisk it into the frosting. This keeps the cake cohesive in flavour and enhances the malty notes.
Dark chocolate frosting instead of white
Swap the white chocolate for dark chocolate if you prefer something less sweet. The frosting becomes deeper and slightly firmer, which works beautifully with the stout sponge.
Orange scented sponge
Add the zest of one orange to the batter. The citrus lifts the richness without changing the texture.
Coffee infused sponge
Dissolve a teaspoon of instant coffee in a tablespoon of hot water and add it to the butter mixture. Coffee enhances cocoa, creating a more intense chocolate flavour.
Serving Suggestions
Serve the cake with softly whipped cream for a lighter contrast, or with a drizzle of warm chocolate sauce if you want something more indulgent. Fresh berries offer a bright, sharp note that balances the richness. A cup of strong tea, espresso or even a small glass of Guinness pairs well with the cake’s malty depth. It also makes a lovely dessert for St Patrick’s Day meals or cosy weekend dinners.
Frequently Asked Questions
Can I make this cake a day ahead?
Yes. The flavour actually deepens by the next day. Store it covered at room temperature, then frost shortly before serving.
Can it be frozen?
The unfrosted sponge freezes well for up to two months. Wrap it tightly in two layers of cling film. Thaw at room temperature before frosting.
Can I replace the Guinness?
You can use another stout with a similar profile. If avoiding alcohol, use strong coffee for depth, though the flavour will be slightly different.
Why does the recipe use baking soda instead of baking powder?
The acidity in Guinness reacts with baking soda, creating a lighter crumb and helping the cake rise evenly.
Can I bake this in a different tin size?
A slightly larger or smaller tin works, but you may need to adjust the baking time. A deeper tin takes longer to cook through.
Can I use Greek yogurt instead of sour cream?
Yes. Use full fat Greek yogurt. It gives a similar tenderness and moisture.
Why is the frosting made with white chocolate?
White chocolate adds body and stability while keeping the frosting smooth and creamy. It also contrasts nicely with the dark sponge.
Can I make this without an electric mixer?
Yes. A wooden spoon and a bit of patience work fine for the batter. For the frosting, a hand whisk gives the best control if you do not have a mixer.
How do I know the cake is fully baked?
A skewer should come out clean, and the centre should feel firm to the touch. If the surface wobbles when gently shaken, give it more time.
