It was my dads birthday yesterday, so I made him this cake. He is a coffee monster, just like me... or I'm just like him... Either way, it's in the genes.
adapted from here
For the Cakes:
2 cups plain flour
2 teaspoons baking powder
1/8 teaspoon baking soda
1/4 teaspoon fine sea salt
140g unsalted butter, at room temperature
1 cup caster sugar
1 egg yolk
2 teaspoon vanilla extract
3/4 cup buttermilk
For the Espresso Extract:
2 tablespoons instant espresso powder
2 tablespoons boiling water
For the Espresso Syrup:
1/2 cup water
1/3 cup caster sugar
For the Mascarpone Filling and Frosting:
1/2 cup icing sugar, sifted
2 teaspoon vanilla extract
1 cup cold cream
1/2 cup dark chocolate, roughly chopped, plus extra for grating
Make the Cakes:
Preheat the oven to 180C. Butter two 23cm round cake pans, coat with flour and line the bottoms with baking paper. Set aside.
On a mixing bowl, sift together the flour, baking powder, baking soda and salt. Set aside.
In an electric mixer fitted with the paddle attachment, beat the butter on medium-high speed until smooth. Add the sugar and beat for a further 5 minutes. Add the eggs and egg yolk one at a time, beating well after each addition. Add the vanilla and reduce the speed to low. Add a third of the flour mixture, followed by half of the buttermilk. Add another third of the flour mixture and the remaining buttermilk. Finally, add the rest of the flour mixture and mix until just incorporated.
Divide the batter between the prepared pans and bake for 22 - 25 minutes, or until a skewer inserted into the centre of the cakes comes out clean. Leave the cakes to cool in the pans for 5 minutes before transferring them to a wire rack to cool completely.
Make the Espresso Extract:
Put the espresso powder into a small bowl, add the boiling water and whisk until smooth. Set aside.
Make the Espresso Syrup:
Put the water and sugar into a small saucepan and bring to the boil. Remove from the heat and stir in a tablespoon of the espresso extract. Set aside.
Make the Mascarpone Filling and Frosting:
Put the mascarpone, sugar and vanilla into a bowl and whisk until blended and smooth.
In an electric mixer fitted with the whisk attachment, whip the cream until firm peaks. Stop the mixer and use a spatula to fold a spoonful of the whipped cream into the mascarpone mixture. Add the remaining whipped cream and gently fold them together.
Assemble the Cake:
Protect the cake stand from drips by lining it with strips of baking paper. Level the cakes if the have risen to a dome and place one cake on the cake stand, bottom-side up. Spoon a third of the espresso syrup over the cake. Spread about 1 cup of the mascarpone cream evenly over it and sprinkle with the chopped chocolate. Put the second cake on the counter, spoon a third of the espresso syrup over it and turn it over and place it, syrup side down on the filling. Spoon the remaining syrup over the top of the cake.
Complete the Frosting:
Whisk 1 tablespoon of the remaining espresso extract into the remaining mascarpone cream. Taste it to see if you want to add more extract for a stronger coffee flavour. Put the frosting in the fridge for 20 minutes to firm up and then spread it evenly over the top and sides of the cake.
Refrigerate the cake for at least 3 hours (or overnight) before serving.
Before serving, grate some dark chocolate over the surface of the cake using a fine microplane. I used a stencil for decoration.