Chocolate, Guinness and potato cake

This above all else we know to be true... Guinness is, first and foremost, an Irish beer, and in Ireland, we have true respect for the potato.

You don’t just buy a bag of generic spuds; you choose between varieties depending on how you’re going to cook them. Each household has its opinions and favorites, debating Cara versus Golden Wonder, Maris Piper over Rooster, Kerr’s Pink, or Home Guard.

This recipe, which gets extra richness from Foreign Extra Stout, makes it easy. Just have your favorite mashed potato for dinner and save some for the cake.

Chocolate, Guinness, and potato cake recipe

Yield: One 7-inch (18cm) round-tiered cake 

Preheat the oven to 350°F (180°C). Grease three 7-inch (18cm) round cake pans with butter and line them with parchment paper.

Ingredients:

Cake:

  • 2 sticks (8 ounces [225g]) of unsalted butter, at room temperature, plus more  for greasing the pan
  • 1 cup (200g) granulated  or caster sugar
  • 1 cup (220g) packed light muscovado sugar
  • 4 medium eggs, at  room temperature
  • 4 ounces (90g) 70% dark chocolate, broken into  pieces and melted
  • 1/3 cup (70g) leftover mashed potato
  • 2 cups (240g) all-purpose flour
  • 1/3 cup (30g) Dutch-processed cocoa powder
  • 1 teaspoon baking powder
  • 1/2 teaspoon baking soda
  • 1/2 cup plus 2 tablespoons (150ml) Guinness Foreign  Extra Stout 

Icing:

  • 1 stick (4 ounces [110g]) unsalted butter, at room temperature
  • 1.5 cups (180g) icing (powdered) sugar, sifted
  • One 8-ounce (225g)  package cream cheese, at room temperature
  • 1 teaspoon vanilla extract
  • Pinch of sea salt

Method 

To make the cake: 

In the bowl of a stand mixer fitted with a paddle attachment, cream the butter, caster sugar, and muscovado sugar together for 3 to 4 minutes, until light and fluffy. Add the eggs, one at a time, beating well after each addition. Mix in the melted chocolate and mashed potato.

In a separate large bowl, sift together the flour, cocoa powder, baking powder, and baking soda. Working in three additions, gently mix the flour mixture into the butter-sugar mixture, adding a third of the beer after each addition. 

Divide the batter evenly among the prepared pans and bake for 20 to 25 minutes, or until the cakes feel springy and a cake tester comes out clean from the center. Cool in the pans for 10 minutes, then turn the cakes onto a wire rack and allow to cool completely.

To make the icing: 

In a medium bowl, beat the butter and icing sugar together until smooth, then mix in the cream cheese, vanilla, and salt until well combined.

Put the first cake layer on a serving platter and use an offset spatula to spread with ¾ cup (170g) of icing. Top with another cake layer and spread with ¾ cup (170g) of icing. Top with the remaining cake layer and spread the remaining icing across the top of the cake. 

Chill in the fridge for 1 hour to set the icing. Store for several days in an airtight container in the fridge, but bring to room temperature before serving.

* Originally published in 2022, updated in June 2023.