Single Layer Guinness Cake with Irish Cream Frosting
This flavorful single layer, egg-free Guinness cake with Irish cream frosting comes together in under an hour, perfect for St. Patrick's Day celebrations!
Prep Time 20minutes
Cook Time 35minutes
Total Time 55minutes
Servings 18-inch square cake (9-16 servings)
For the cake:
1 1/2cupsall-purpose flour
1/4cupcocoa powder(can use natural or Dutch process)
1/2teaspoonespresso powder(optional; brings out chocolate flavor)
1cupGuinness(or another stout beer)
1tablespoonapple cider vinegar(or white vinegar)
For the frosting:
4ouncescream cheese, cold
1/4cup(1/2 stick) unsalted butter, softened to room temperature
2tablespoonsIrish cream liqueursuch as Bailey's or Carolan's
Pinch of salt
For the cake:
Preheat your oven to 350 degrees F. Grease an 8-inch square pan. I also like to line the bottom of the pan with parchment paper, to give extra insurance that the cake will come out cleanly. Just trace the bottom of the pan on a sheet of parchment paper and cut it out, then place inside the pan.
In a large bowl, whisk together dry ingredients: flour, cocoa powder, sugar, salt, espresso powder, and baking soda.
Pour in the wet ingredients: Guinness, olive oil, vanilla, vinegar. Whisk it all together until a smooth batter is formed. You'll notice it might get a little foamy - that's the baking soda/vinegar reaction happening. Stop whisking when the mixture is combined and no lumps remain - don't overmix or the cake will be tough.
Pour batter into prepared pan, and bake for 32-35 minutes, until cake springs back when touched and a tester inserted in the center comes out clean.
Let cake cool in pan on a rack for 10 minutes, then invert the pan onto the rack to release the cake, remove the parchment from the bottom, and flip back right side up onto a cake plate. Let cake cool while you prepare the frosting.
For the Irish cream frosting:
In a large bowl using a stand mixer with the whisk attachment, or a hand mixer, beat cream cheese and butter at high speed until pale and very fluffy - this should take 2-3 minutes. You want to incorporate as much air as possible into the mixture to make it light and fluffy. Add the powdered sugar, Irish cream, and salt, and beat at medium to high speed until fully combined and light.
Spread cooled cake with Irish cream frosting. It should make a thick layer, and can be swirled in pretty patterns with an offset spatula (I like this one). Serve!