British Coffee and Walnut Cake with Coffee Buttercream

👨‍🍳 Method

To assemble

1. 1
   Preheat the oven to 180°C (355°F) and grease Springform pan of 24 cm.

   ⚙ Preheating the OvenOven

   💡Put things in the oven only once it's reached temperature, after the heating light has gone off: an oven that hasn't reached temperature changes baking times, and the bake burns outside or stays underbaked.
2. 2
   Whip the soft butter with the sugar, until pale and fluffy.

   ⚙ WhippingBowlHand mixerorStand mixerorWhisk

   💡Cream the butter soft, at room temperature: cold butter doesn't take in air, and melted butter doesn't hold it.
3. 3
   Add the eggs one at a time, beating after each until absorbed.

   💡One egg at a time, and only when the previous one is absorbed: that way the emulsion holds and the batter doesn't split into curds.
4. 4
   Add the coffee and vanilla and mix.
5. 5
   Add the flour, baking powder and salt and Fold gently, just until no dry flour remains.

   ⚙ FoldingSilicone spatula

   💡Fold with a spatula, in broad strokes from the bottom up, and stop when there's no dry flour: vigorous mixing of a batter with flour develops gluten.
6. 6
   Add the chopped walnuts and Fold gently.

   ⚙ FoldingSilicone spatula
7. 7
   Pour into the pan.

   Baking pan
8. 8
   Bake 35–40 minutes, until a toothpick inserted in the center comes out clean.

   ⚙ BakingOvenBaking pan

   💡Check by the cue (until…), not just the clock: every oven bakes a little differently.
9. 9
   Let the cake cool completely.
10. 10
    Whip the soft butter on its own, until fluffy and pale.

    ⚙ WhippingBowlHand mixerorStand mixerorWhisk

    💡Room-temperature butter whips into a smooth cream: cold butter stays lumpy, and melted butter won't hold the air.
11. 11
    Add the powdered sugar in two or three additions, then the coffee, and keep whipping until the cream is smooth.

    Hand mixerorStand mixer
12. 12
    Spread the cream over the cake.

    Offset spatula