Biblicook's Chocolate, Porter and Potato Cake
Blogger Caroline Hennessy shares her unusual but festive recipe for the perfect Paddy's Day cake.

Spuds and stout, potatoes and porter. Can you think of anything more Irish? And would you put them together in a chocolate cake? Read on – you just might be convinced!

With St Patrick's Day coming up, you'll see numerous pictures of and references to a particular big brand of stout. For a lot of people, Irish beer is synonymous with this particular dark, creamy pint. Until recently there was precious little choice available in Ireland. That's all changing now and small microbreweries, dotted throughout the country from Roscommon to Rathmullan, Dungarvan, Kinsale and Templemore are taking on the big boys to deliver beers with taste, flavour and provenance.

I first tasted good beer in New Zealand; the Kiwi that came home with me went off and set up Eight Degrees Brewing in Mitchelstown, Co Cork with an Aussie friend. The result? Being married to a brewer means not only do I get a chance to try lots of really great beers and pair them with food, I also get to use them in my kitchen. So it's pale ale in mustard or blondies, pilsner added to pizza dough, cheese bread made with red ale and – my ultimate favourite – dark, malty stouts and porters in chocolate cakes and brownies. It's not as strange as it sounds. Take an Irish craft stout, pour it into a glass and take a wee taste; those roasted, toasty, espresso and cocoa flavours are just the thing to enhance chocolate.

Take that one step further by adding some mashed potatoes, possibly homegrown or bought locally, and you have a seriously epic, truly Irish cake that makes a perfect St Patrick's Day treat. How can you possibly resist?

Epic Chocolate, Porter and Potato Cake

Serves 8-10

Ingredients:

  • Any good Irish craft porter or stout is worth trying in this cake, some of my favourites are Carlow Brewing Company’s Leann Folláin, Dungarvan Brewing’s Coffee and Oatmeal Stout, Russian Imperial Stout from White Gypsy, Eight Degrees' Knockmealdown Stout or, for another layer of flavour, the Ginger Porter from Rascal's Brewing.
  • 75g dark chocolate with 70% cocoa solids
  • 225g butter, at room temperature
  • 200g caster sugar
  • 220g light muscovado sugar
  • 4 eggs, at room temperature
  • 75g mashed potato. Leftovers from last night's dinner are fine.
  • 250g plain flour
  • 25g cocoa
  • 1 teaspoon baking powder
  • 1/2 teaspoon bicarbonate of soda
  • 150mls porter or stout
  • Cream cheese icing:

  • 200g cream cheese, at room temperature
  • 50g butter, at room temperature
  • 50g icing sugar, sifted
  • Method:

  • Preheat the oven to 180°C (160°C fanbake) and line the base of a 23cm round baking tin.
  • Melt the chocolate and allow to cool. Cream the butter and sugars together in a large bowl then add the eggs, one at a time, beating well between each addition. Mix in the melted chocolate and mashed potato (a sentance you won't come across in your regular chocolate cake recipe!).
  • Sift the flour, cocoa, baking powder and bicarbonate of soda together. Gently mix into the cake batter in three additions, alternating with the porter or stout. Pour and scrape into the prepared tin, leveling the surface with the back of the spoon, and bake for 60-70 minutes or until the cake feels springy and a skewer comes out clean from the centre.
  • Cool in the tin for 10 minutes then remove to a cooling rack and allow to cool completely.
  • To make the icing, beat the cream cheese and butter together until smooth (having them at room temperature makes this so much easier), then mix in the icing sugar. Spread over the cake and dust with a little cocoa.
  • Match it with vanilla ice cream, strong coffee and/or the rest of the beer – unless you polished that off during the washing up. Don't worry. I won't tell anyone.
  • More beer

    The Irish Beer and Whiskey Festival takes place in the RDS over St Patrick's Weekend, from 13 to 17 March. Not a green-dyed pint to be found.

    Read more here