by Regula Ysewijn from ‘Oats in the North, Wheat from the South’ (Murdoch Books)
Photography: Regula Ysewijn
Coffee and walnut cake can be found in every tearoom. Even though it’s old fashioned, it hasn’t fallen out of favour. You can make one cake and decorate it with buttercream or you can make several layers with buttercream in between.
You can make buttercream in several different ways. Italian buttercream is made with Italian meringue, which is made by whipping egg whites together with hot sugar syrup. The meringue is then beaten until it has cooled, after which the butter is added. This buttercream has a very white appearance. For Swiss buttercream, a mixture of egg white and sugar is heated in a bain marie at 71°C (160°F), then the egg whites are whipped and butter is added. The French method isn’t that different: they first make a pâte à bombe by boiling water with sugar at 121°C (250°F). In the meantime, they whip the egg whites, then add the sugar syrup and beat until cold. Subsequently, cubes of butter are added to create a creamy, smooth buttercream. The Germans do it completely differently and make a mousseline cream that consists of 1 part butter and 2 parts pastry cream. There are many more versions, but here I’ve used the simplest, which is the English or American version. This buttercream is not really smooth, but its advantage is the simplicity – anyone can make it.
For 6–8 people
For the cake
225 g (8 oz) butter, at room temperature
200 g (7 oz) raw (demerara) sugar
225 g (8 oz) plain (all-purpose) flour
3 tsp instant coffee dissolved in
1 tbsp hot water, cooled
pinch of cocoa powder
pinch of ground cinnamon
pinch of sea salt
2 tsp baking powder
75 g (2½ oz) walnuts, roughly chopped
walnut halves, to garnish
butter, for greasing
flour, for dusting
For the buttercream
240 g (8½ oz) butter, at room temperature
400 g (14 oz) icing (confectioners’) sugar
2 heaped tsp instant coffee dissolved in
1 tbsp hot water, cooled
For two 18–20 cm (7–8 inch) round cake tins
Preheat your oven to 180°C (350°F) and prepare the tins.
For a round tin, apply a thin layer of butter with a folded sheet of paper towel and divide it nicely around the edge of the baking tin. Apply a layer of baking paper to the bottom of the baking tin: trace around the tin onto the baking paper, then cut out the circle. Stick the baking paper to the butter so that the paper stays in place. Dust the lined tin with flour, hold the tin above your workbench or sink and tap on the bottom to remove the excess flour.
Put the butter and sugar in a bowl and beat until creamy. Add the eggs, one at a
time, and make sure that each egg is completely incorporated before adding the
next one. Add a teaspoon of the flour with the last egg to prevent the mixture
from separating. Stir in the instant coffee, cocoa, cinnamon and salt.
Carefully fold the remaining flour and the baking powder into the batter so that
the volume is retained. Mix in the walnuts, divide the batter between the cake tins
and smooth the tops. Firmly tap the tins on the bench to distribute the batter and
remove any air bubbles. Bake in the middle of the oven for 20–25 minutes.
Let the cakes rest for 5 minutes before taking them out of the tins, then let them
cool further on a wire rack.
For the buttercream, beat the butter in an electric mixer until it turns white;
this is an important step. Add the icing sugar, one spoonful at a time, until it
is completely absorbed. Finally, add the instant coffee and mix well until the
buttercream is fluffy.
To assemble the cake, choose the cake with the smoothest top and set it aside.
Spread the other cake with buttercream or use a piping bag fitted with a star
nozzle to pipe a pattern over the cake. Place the second cake on top and lightly
press down. Decorate the top of the cake with buttercream and walnut halves.