Miso Walnut Cakes with Espresso Buttercream

It feels odd to write about cake with everything that has been happening this week. But with all the terrifying stories in the news, I guess we could all use some cheering up right about now. So cake it is. More specifically miso walnut cakes with espresso buttercream.

Coffee and Walnut is a classic cake pairing. So while I did not want to mess with the original idea too much, it was about time Miso and Walnut met in a sweet context. For quite some time now, one of my go-to easy dinners has been Heidi Swanson’s recipe for Miso Walnut Noodles. You make a pesto of sorts with walnuts, olive oil, garlic, white miso, some vinegar, honey and salt and that you stir through some pasta. The bitterness and delicate crunch of the walnuts is the perfect contrast to the creamy and sweet and slightly funky-tasting miso – the paste is so good I tend to make a big batch to keep in the fridge for sandwiches, cooked pasta and greens.

While Heidi’s Miso Walnut Noodles are decidedly savoury, her recipe made me realize how well walnuts and miso go together. And we already know how much I like using miso in sweets. While it lends a beautiful savoury note to custards and caramel or butterscotch (and in a less direct and less aggressive way than sea salt does), baking with miso I noticed how it can make things taste ‘malty’. A brilliant discovery when malted milk powder can be hard to track down and given my fridge already sports several jars of miso.

These little miso walnut cakes don’t contain a whole lot of miso. Like salt, miso is powerful and a mere teaspoon is enough to give these cakes a bit of a malty flavour and really underline the flavour of the toasted walnuts. The cakes are topped with a lick of espresso buttercream – enough for these little cakes to feel a bit more indulgent but without being cloying.

 

Miso Walnut Cakes with Espresso Buttercream

Note: Makes 6 small cakes. Recipe for the espresso buttercream lightly adapted from the Hummingbird Bakery Book

Ingredients

50g walnuts (plus 6 additional walnut halves for decoration if you like)
50g brown rice flour
75g butter, at room temperature
50g light muscovado sugar
2 eggs, separated
1 tsp white miso

For the espresso buttercream
40g soft butter
125g icing sugar
2 tsp soluble espresso powder
2 tbsp milk

Directions

Pre-heat the oven to 180 degrees Celsius and grease a 6 hole muffin tin (or 6 similarly sized individual cake tins such as friand moulds).

Toast the walnuts in a dry pan on medium heat until fragrant, being careful not to burn them. Pulse in a food processor until the walnuts turn into a fine meal (but before they start turning into walnut butter!). Add the rice flour and whisk to combine. Set aside.

In a mixing bowl, beat the soft butter with the sugar until pale in colour and doubled in volume (this should take ca. 4-5 minutes). Add the egg yolks and the miso paste and beat well to incorporate. Incorporate the flour and walnut mixture 3 portions, mixing well in between each addition.

Beat the egg whites until stiff before carefully folding them into the batter.

Carefully distribute the batter between the muffin tin holes/cake tins.

Bake for 20-25 minutes until well risen and the cakes are just starting to colour.

Leave the cakes to cool for 5 minutes before carefully removing them from their tins and placing on a cookie rack to cool down completely.

To make the buttercream beat the butter with the icing sugar and espresso powder on medium speed until combined (the mixture will look impossibly dry at first but should come together after 3-4 minutes). Add the milk and continue beating util the mixture is light and fluffy (at least 5 minutes). Using a spoon or a small spatula, carefully spread about 1 scant tablespoon of buttercream on top of each small cake. Decorate with the walnut halves if using.