Help please. I used ground espresso for the Coffee and Walnut Cake and I don't think it is what I should have used. It is a bit gritty. Ideas please. Cake tastes ok but icing not so great!
Nigella's Coffee And Walnut Layer Cake (from KITCHEN) has a walnut-enriched sponge that is flavoured with coffee and is sandwiched and filled with a coffee-flavoured buttercream. Nigella suggests using instant espresso for the cake, as it dissolves easily and has a good flavour.
Unfortunately regular ground espresso is not quite the same - the coffee grinds are still quite large. You may not notice this so much in the cake, as it also contains ground walnuts, but the buttercream will be too gritty. Instant espresso powder has been reinvented as "microground coffee" and is available in many supermarkets. If you can't find this then you could use instant coffee, but it needs to be dissolved first. For the sponge you will need about 4½ teaspoons of instant coffee and we suggest warming the 2 tablespoons of milk and dissolving the coffee in this, letting it cool and then adding it to the cake batter. For the buttercream use 3 teaspoons of instant coffee dissolved in the boiling water.