Can I Make The Frosting On The Old Fashioned Chocolate Cake Less Sweet?

Our answer

Nigella's Old Fashioned Chocolate Cake (from FEAST) is a chocolate sponge layer cake that is filled and coated with a rich chocolate frosting. The frosting is a fudgy mixture that is made from melted butter and chocolate that has icing (confectioners') sugar and sour cream added. The icing sugar adds sweetness and a little structure, though not as much as for a simple buttercream.

The chocolate will help the frosting to set as it cools. Our main concern would be that by reducing the sugar too much, the frosting will not be sweet enough due to the combination of dark (bittersweet) chocolate and sour cream or it may lack flavour as sugar is a flavour enhancer. We would suggest initially making the frosting with the lower amount of sugar and then tasting it to see if it is to your liking. At this point you can always add a little more sugar if necessary. If the frosting is too runny, you can try refrigerating it for a short time, stirring regularly, to see if it thickens up and if it doesn't then you may need to beat in a little extra icing sugar to make it a little thicker and spreadable.