Howcome no one told me it was so hard to frost cakes?? Well, okay, actually I’ve heard that a million times, but… they make it look so easy on TV! You can see my amateur cake frosting on this coffee and walnut cake here, but I promise you that this cake was very straightforward and easy to make, and for anyone with even a *little* bit of experience frosting cakes, I’m sure you’ll have a far prettier cake than I did. And this cake is so, so good that it doesn’t matter how “homespun” (to use Nigella Lawson’s term) it looks – it will be devoured.
This cake has walnuts throughout the batter, walnuts that have been whizzed up with sugar in the food processor, creating the most delicious walnut-sugar powder (I admit, I tried it straight out of the food processor). And yes, basically the whole shebang – batter and frosting – can all be made in your food processor (thanks, Nigella!).
The frosting and the cake also have instant coffee (or espresso, if you’d like) strewn through it, giving it enough of a complex, bitter edge to round out the sweetness of the cake. The combination of the coffee icing and walnut batter almost reach a toasty caramel-like status.
Easy Coffee and Walnut Cake
adapted slightly from Nigella Lawson via New York Times
For the cake:
Butter for pans
½ cup (60 grams) walnut pieces
1 cup plus 2 tablespoons (245 grams) sugar
2 sticks (8 ounces) unsalted butter at room temperature
1 ⅔ cups (230 grams) flour
1 tablespoon (14 grams) baking powder
½ teaspoon salt
4 large eggs
2 tablespoons milk at room temperature
1 tablespoon (3 grams) instant coffee dissolved in 1 tablespoon boiling water
For the frosting:
5 cups (600 grams) confectioners’ sugar
1/4 teaspoon salt
3 sticks (12 ounces) unsalted butter at room temperature
2 tablespoon (6 grams) instant coffee dissolved in 2 tablespoon boiling water
about ¼ cup walnut halves, for decoration
First, make the cakes:
Preheat your oven to 350 degrees. Butter two 8-inch cake pans and line them with parchment paper for easy removal.
In a food processor, place 1/2 cup of walnut pieces and the sugar, and process them until they’re finely powdered. Add in the butter, flour, baking powder, salt and eggs, and continue to process to a smooth consistency.
Add 2 tablespoons of milk to the coffee/water mixture and pour it into the food processor using the feed tube while the blade is running. After this, the batter should be soft and drop from a spoon (instead of sticking to it). If your batter isn’t runny enough, add a bit more milk as needed until it just drops from a spoon.
Divide the cake batter evenly between the two pans. Bake 25 minutes or until cake is risen and slightly springy to the touch. Allow the cakes to cool in the pan on a rack for about 10 minutes and then remove them from the pans, take off the parchment paper, and let them cool completely on the rack.
If the cakes have domed in the oven, level the tops with a serrated knife so that the tops are completely flat.
Then, make the frosting:
Add confectioners sugar and salt to the (clean and dry) food processor, and pulse it together until there are no lumps. Add in the room temperature butter and process until totally smooth. Add coffee mixture down the feed tube as before, then pulse the processor until everything is blended together completely.
To frost the cake, place one of the cakes upside down on a cake stand or a flat plate. Spread a little less than half of the frosting all over the top. then place the second cake (right side up) on the frosting and ice the top of it, making a swirl pattern if you like. Feel free to leave the sides of the cake bare or frost them completely. *Note: this makes a lot of frosting, so you don’t necessarily need to use all of it – it’s just better to have too much than not enough!
Press walnut halves into the top of the cake to decorate as you’d like.
Store in an airtight container for a few days to a week, or freeze in slices if you’d like.