Good news! I made my husband the ultra-British coffee and walnut cake that I had promised! Even better, it was actually really good, thanks to a recipe from Nigella Lawson’s Nigella Kitchen cookbook!

Her version is very simple, particularly since all of the ingredients go straight into the food processor and are blitzed.

The “coffee” ingredient she recommends is instant espresso powder, which I didn’t even know existed, but was easy to find in our nearest grocery store.

After exactly 25 minutes, they were ready.

I waited 10 minutes as instructed before moving the cakes to the cooling racks. The cakes just eased out of the pans, as if on cue. It was amazing.

The frosting was also very simple to make (powdered sugar, butter and instant espresso powder in a little bit of boiling water) but was easily the best buttercream frosting recipe I’ve ever made. I was exceedingly proud of how pretty this cake turned out – just look!

I’ll definitely make it again in non-birthday circumstances. I can easily see this turning into my go-to cake to bake! Note: if you’re making the cake for kids, you can always tone down the caffeine quotient by replacing the 4 teaspoons of instant espresso powder with 2 teaspoons of instant coffee granules. (Or you can just serve it first thing in the morning and call it breakfast).

COFFEE AND WALNUT LAYER CAKE

For the sponge
1/2 cup walnuts (pieces)
1 cup plus 2 tablespoons superfine sugar
2 sticks unsalted butter (soft (plus some for greasing))
1 1/3 cups plain flour
4 teaspoon(s) instant espresso powder
2.5 teaspoon(s) baking powder
½ teaspoon(s) baking soda
4 medium egg(s)
2 tablespoon(s) milk

For the buttercream frosting
3 1/4 cups powdered sugar
1 1/2 sticks unsalted butter (softened)
2.5 teaspoon(s) instant espresso powder, dissolved in 1 tablespoon boiling water
approximately 10 walnut halves

Preheat the oven to 350 degrees. Butter the 2 8-inch round cake pans and line the base of each with parchment paper.
Put the walnut pieces and sugar into a food processor and blitz to a fine nutty powder.
Add the 2 sticks of butter, flour, 4 teaspoons espresso powder, baking powder, baking soda and eggs and process to a smooth batter.
Add the milk, pouring it down the funnel with the motor still running, or just pulsing, to loosen the cake mixture: it should be a soft, dropping consistency, so add more milk if you need to. (If you are making this by hand, bash the nuts to a rubbly powder with a rolling pin and mix with the dry ingredients; then cream the butter and sugar together, and beat in some dry ingredients and eggs alternately and, finally, the milk.)
Divide the mixture between the 2 cake pans and bake in the oven for 25 minutes, or until the sponge has risen and feels springy to the touch.
Cool the cakes in their tins on a wire rack for about 10 minutes, before turning them out onto the rack and peeling off the parchment paper.
When the sponges are cool, you can make the buttercream.

To make the frosting:
Pulse the powdered sugar in the food processor until it is lump free, then add the butter and process to make a smooth icing.
Dissolve the instant espresso powder in 1 tablespoon boiling water and add it while still hot to the processor, pulsing to blend into the buttercream.
If you are doing this by hand, sieve the icing sugar and beat it into the butter with a wooden spoon. Then beat in the hot coffee liquid.
Place 1 sponge upside down on your cake stand or serving plate.
Spread with about half the icing; then place on it the second sponge, right side up (i.e. so the 2 flat sides of the sponges meet in the middle) and cover the top with the remaining icing in a ramshackle swirly pattern.
This cake is all about old-fashioned, rustic charm, so don’t worry unduly: however the frosting goes on is fine. similarly, don’t fret about some buttercream oozing out around the middle: that’s what makes it look so inviting.
Gently press the walnut halves into the top of the icing all around the edge of the circle about 1/2 inch apart.

Cuts into 8 generous slices.