Preheat oven to 160°C fan
Make the coffee mix and set aside to cool
Add eggs, cornflour, flour, baking powder and sugar to your mixing bowl and use a wooden spoon to bring together
Add the very soft melted butter not warm butter to the coffee mix and add that to your bowl
Use a whisk to bring all together
Pour into your parchment lined tray or flour and butter lined tins
Bake for half and hour
Remove from oven and take from the cake tins after ten minutes too cool on a wire rack - I leave the traybake in the tins until I ice it though
To make the buttercream beat the butter with the K beater until it's fluffy - about five minutes
Add the icing sugar in four lots, beating each time to a buttercream consistency
Finally add the tbsp of coffee flavouring
Beat once more
