1½ level tablespoons instant coffee mixed with 2 tablespoons boiling water
3 oz (75 g) walnut halves
6 oz (175 g) self-raising flour
1½ level teaspoons baking powder
6 oz (175 g) softened butter
6 oz (175 g) golden caster sugar
3 large eggs at room temperature
1 level tablespoon instant espresso coffee powder
1 rounded tablespoon golden caster sugar
10 walnut halves, reserved from the sponge cake
9 oz (250 g) mascarpone
7 fl oz (200 ml) 8 per cent fat fromage frais
Pre-heat the oven to gas mark 3, 325°F (170°C).
Lightly grease two 8 inch (20 cm) sandwich tins, 1½ inches (4 cm) deep and line the bases with silicone paper (baking parchment).
Toast all the walnut by spreading them on a baking sheet and place in the pre-heated oven for 7-8 minutes.
Reserve 10 halves to use as decoration later and finely chop the rest.
In a mixing bowl, put the flour and baking powder in a sieve and sift it into the bowl, holding the sieve high to give it a good airing as it goes down.
Add all the other cake ingredients (except the coffee and walnuts) to the bowl and, provided the butter is really soft, whisk everything together with an electric hand whisk until you have a smooth, well-combined mixture.
Then carefully fold in the coffee and chopped walnuts. You should end up with a soft mixture that drops off the spoon easily when you give it a sharp tap; if not, add a spot of water.
Divide the mixture between the prepared sandwich tins, spreading the mixture around evenly.
Place the tins on the centre shelf of the oven and bake for 30 minutes.
While the cakes are cooking you can make up the syrup and the filling and topping.
For the syrup, place the coffee and sugar in a heatproof jug, then measure 2 fl oz (55 ml) boiling water into it and stir briskly until the coffee and sugar have dissolved. This will take about 1 minute.
Next prepare the filling and topping.
Place all the ingredients, except the reserved walnuts, in a bowl and whisk them together till thoroughly blended. Then cover the bowl with clingfilm and chill till needed.
When the cakes are cooked, ie, feel springy in the centre, remove from the oven but leave them in their tins and prick them all over with a skewer while they are still hot.
Now spoon the syrup as evenly as possible over each one and leave them to soak up the liquid as they cool in their tins.
When they are absolutely cold, turn them out very carefully and peel off the base papers – it's a good idea to turn one out on to the plate you're going to serve it on.
Spread half the filling and topping mixture over the first cake, place the other cake carefully on top and spread the other half over.
Finally, arrange the reserved walnut halves in a circle all around.
It's a good idea to chill the cake if you're not going to serve it immediately.
Recipe by Doe's Kitchen at http://doeskitchen.com/coffee-and-walnut-cake/