Ingredients
250g pack softened butter, plus extra for the tins
100ml strong black coffee (made with 2 tbsp coffee granules), cooled
280g self-raising flour
250g golden caster sugar
½ tsp baking powder
4 eggs
1 tsp vanilla extract
85g walnuts, 2 tbsp roughly chopped, the rest finely chopped
For the filling
100g icing sugar, sifted, plus a little extra for dusting
150ml double cream
100g mascarpone, at room temperature