Coffee and Walnut Layer Cake

🥘 Ingredients

• walnut pieces 50 g
• caster sugar 225 g
• soft unsalted butter 225 g
• plain flour 200 g
• instant espresso powder 4 tsp
• baking powder 2 ½ tsp
• baking soda ½ tsp
• large eggs 4
• milk 2 Tbsp
• icing sugar 350 g
• soft unsalted butter 175 g
• instant espresso powder 2 ½ tsp
• boiling water 1 Tbsp
• walnut halves 10

1. 1

   Preheat the oven to 180°C / 160°C fan / 350°F (gas mark 4).
2. 2

   Butter two 8-inch (20cm) sandwich cake pans and line the bottom of each with baking parchment .
3. 3

   Put walnut pieces and caster sugar into a food processor and blitz to a fine nutty powder.
4. 4

   Add soft unsalted butter , plain flour , instant espresso powder , baking powder , baking soda , and large eggs and process to a smooth batter.
5. 5

   Add 1 to milk , pouring it down the funnel with the motor running or pulsing, to loosen the cake mixture to a soft, dropping consistency. (If making by hand, bash the nuts to a rubbly powder with a rolling pin and mix with the dry ingredients; cream the butter and sugar together, then beat in dry ingredients and eggs alternately, followed by the milk.)
6. 6

   Divide the mixture evenly between the 2 lined pans and bake in the oven for 25 minutes , or until the sponge has risen and feels springy to the touch.
7. 7

   Cool the cakes in their pans on a wire rack for about 10 minutes , before turning them out onto the rack and peeling off the baking parchment to cool completely.
8. 8

   To make the buttercream, pulse icing sugar in the food processor until lump-free, then add soft unsalted butter and process to make a smooth icing.
9. 9

   Dissolve instant espresso powder in boiling water and add it while still hot to the processor, pulsing to blend into the buttercream. (If making by hand, sieve the icing sugar and beat it into the butter with a wooden spoon, then beat in the hot coffee liquid.)
10. 10

    Place 1 sponge upside down on a cake stand or serving plate. Spread with about half the buttercream frosting, then top with the second sponge right side up so the two flat sides meet in the middle. Cover the top with the remaining icing in a swirly pattern.
11. 11

    Gently press walnut halves into the top of the icing around the edge of the circle about 1 cm apart.