The earliest recipe that I have found for Coffee Walnut Cake is Mrs Beetons. In her 1861 tome ‘Household Management’, she mixes shredded walnuts into a Genoa sponge, tops it off with coffee icing (which is made by boiling a gill of water with a pound of icing sugar and mixing in coffee essence) and she decorates it with walnut halves. The accompanying picture shows it carefully placed on a doily (whatever happened to doilies?), with additional flourishes of icing and with its sides covered in some unidentifiable ingredient (presumably chopped walnuts).
Although the recipe for Coffee Walnut Cake hasn’t changed too much in the past 15o years the way that ingredients are brought and selected certainly has. Mrs Beeton helpfully suggests that when selecting butter we ‘plunge a knife into it, and if, when drawn out, the blade smells rancid or unpleasant, the butter is bad’. 😀
She suggested that before buying coffee one should check to insure that it hadn’t been adulterated with chicory. To do this she suggested throwing a teaspoon of it in to a tumbler of water, if the coffee was pure it would float, if it had been meddled with then the chicory would sink and discolor the water. She also encouraged testing sugar for pureness by placing a small amount in an iron ladle, burning it and checking what you are left with. Impure sugar would leave an ash behind, pure sugar wouldn’t.
How Mrs Beeton checked the freshness of eggs may need to stay with Mrs Beeton for now. When googling the apparatus that she used to do this (no best before dates stamped on eggs in those days) some very unsavory websites popped up 😬 – it wasn’t old baking techniques that I was being educated about . So for now, I’m not doing any further research on this, I’m just thankful to Henrietta, the chicken who lives down the road, for providing me with very fresh eggs.
I do hope that you enjoy this Coffee Walnut Cake, if you make it. I made a rather decadent three layer cake, but you can easily reduce the ingredients by 1/3 to make a two layer cake. The icing quantities provided are to fill a three layer cake and to fully cover the outside of the cake. I topped my cake with a good layer of the buttercream and then iced the sides with just a little icing, letting parts of the sponge show through. This obviously left me some icing left over which I have frozen (it should keep in the freezer for 2 months).