Coffee and Walnut Cake
STORY AND PHOTOS BY PAOLA THOMAS
This Brit was somewhat bemused when she first arrived in the U.S. and was offered a slice of “coffee cake.” How could there be so many kinds of coffee cake? Why were so many disappointingly dry? And, most puzzlingly of all, why did none of them taste of coffee? The truth is, I was expecting a cake rather like this one: rich, decadently frosted, and, crucially, coffee-flavored.
A coffee and walnut cake — a sponge cake loaded with chopped walnuts, sandwiched and swirled with a luscious coffee buttercream — is a very British confection, found everywhere in my homeland. It’s the sort of unassuming, but deeply satisfying, cake served by tea shops and mothers-in-law, or brought to picnics and potlucks.
The internet can’t tell me which genius first decided to combine walnuts and coffee, but the cozy, roasted, nutty flavors swirl together to create the cake equivalent of hot-buttered toast and knitted sweaters. This earthy flavor profile seems particularly well-suited to the Pacific Northwest, where coffee courses through our veins, and walnuts grow locally and are often available at this time of year on farmstands and in farmers markets. Buy them now when they’re at their freshest and sweetest and store them in the freezer for future use.
I’ve added a few touches of my own to the traditional recipe — using buttermilk and almond flour in the cake batter for extra tenderness, and layering on notes of caramel and spice with brown sugar and maple syrup — to create an indulgent antidote to a dreary late fall afternoon, and, yes, the perfect cake to accompany a steaming cup of joe.
Note: Using instant coffee powder allows for a stronger coffee flavor without making the batter too wet. If you’d prefer a more subtle hint of coffee, either reduce the number of teaspoons of instant coffee, or make the equivalent volume of strong espresso.
Makes 1, 2-layer, 8-inch cake | Serves: 10–12 | Start to finish: 2 hours, including baking and cooling time (active time: 40 minutes)
For the sponge cake
1 1/2 cups all-purpose flour
1 1/2 teaspoons baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
2/3 cup almond flour
1 cup (2 sticks) butter, at room temperature (plus extra for greasing the pans)
3/4 cup granulated or baker’s sugar
1/2 cup soft brown sugar
1 cup walnut pieces (make sure they’re fresh and sweet, not bitter or rancid)
1/2 cup buttermilk or plain yogurt
4 teaspoons instant coffee powder or granules, dissolved in 1 tablespoon hot water (or one shot of extra-strong espresso)
For the filling and icing
1 1/2 cups butter (3 sticks), at room temperature
1/2 teaspoon salt (or use lightly salted butter)
6 cups confectioners’ sugar, sifted
3 teaspoons instant coffee powder or granules, dissolved in 1 tablespoon hot water (or one shot of extra-strong espresso), set aside to cool
1 tablespoon maple syrup
2 tablespoons heavy or whipping cream
Walnut halves to decorate
You can make a slightly less decadent cake by reducing the icing’s butter to 1 cup (2 sticks) and the confectioners’ sugar to 4 cups and only filling and topping the cake with frosting, leaving the sides bare.
Thoroughly butter two 8″ x 2″ layer cake pans, and line the bases with a circle of baking parchment. Preheat oven to 325°F.
Sift the flour, baking powder, baking soda, and salt into a bowl and whisk in the almond flour.
Using a stand mixer, cream the butter and sugars together until light, fluffy, and pale, beating on a medium speed 3–5 minutes.
In the meantime, finely chop the walnuts with a sharp knife. I like a bit of crunch to my cake, but feel free to whizz the nuts to a powder using a food processor, if you prefer.
Stir the chopped walnuts into the creamed butter and sugar, then add the eggs, one by one, with a tablespoon of the flour mixture between each egg addition. Beat, well, scraping down the sides of the bowl as necessary.
Using a metal spoon or spatula, gently fold in the remaining flour, buttermilk, and coffee, retaining as much air in the batter as you can. You should end up with a mousse-like mix that slides reluctantly off a metal spoon.
Divide the batter evenly between the pans, and bake 30–35 minutes or until the cakes are golden brown, their centers feel firm to the touch, and a skewer stuck into the middle of the cake comes out clean. Allow the cakes to cool for 10 minutes in the pans, and then turn the cakes out onto a wire rack to cool completely.
Make the buttercream frosting by beating together the butter, salt, and confectioners’ sugar, using a stand mixer, until very light and pale, 3–5 minutes. Stir in the coffee, maple syrup, and cream. Use about a third of the frosting to sandwich the cakes together, turning the top cake over, so that its flat bottom is uppermost for frosting. Swirl the rest of the frosting over the cake with an offset spatula, and decorate with walnut halves. This is traditionally a somewhat homespun cake, so there is no need for fancy piping skills.
Paola Thomas is a keen home cook and baker and regular contributor to Edible Seattle. She loves playing with flavors in everything from cocktails to salads. Check out her food photography and other writing at paolathomas.com.