Gunpowder cake

Why it's called gunpowder cake, I don't know. The recipe comes from a book that seems to have disappeared from my shelves, published by the Royal College of Art sometime last century, with contributions from various staff members - not just recipes, but drawing to go with them. (Used copies are obtainable for a pittance (plus postage; it was published in 1987, before recipes went into grams etc.)

Instead of eggs, this wartime recipe uses vinegar (and baking soda) as a raising agent. We find that, rather than icing, whipped cream is the best filling and topping. Though a whipped cream filling and a chocolate glaze is nice too.

My copy of the recipe has been much annotated, to fit various pan sizes, so much so that I can no longer make sense of it!

Let's start with the original recipe, converted to metric. If you are using plain flour, add 5ml (a teaspoon) of baking powder for every 100g flour. If you've run out of cocoa but happen to have some drinking chocolate on hand, substitute it for the sugar and cocoa - just add up the grams of the two ingredients.

First, heat the oven to 190C, 375F, gas 5. Butter the baking tin(s) - I usually flour them too.

Gunpowder Cake - for 8" round pan (20cm)

Sieve into bowl:
160g self-raising flour (1-1/2 cups)
125g sugar (1 cup)
30g (2 Tbsp) cocoa 
1 tsp bicarbonate of soda (baking soda)
Melt 150g butter (or use spreadable butter) (5 ounces)
Add to bowl with
2 Tbsp vinegar
250ml warm water (1 cup)
splash vanilla
Mix. Put in well-greased tin. Bake at 190C (375F) for 40 mins, till cake pulls away from the edges of the pan and springs back when touched lightly.


For an 8" (20cm) square pan, or two 7" (18cm) tins [a very British size], use 1-1/2 times the recipe -

Sieve into bowl:
210g self-raising flour
125g sugar [we like it less sweet]
45g (3 Tbsp) cocoa
1-1/2 tsp bicarbonate of soda (baking soda)
Melt 225g butter (or use spreadable butter)
Add to bowl with
3 Tbsp vinegar
340ml warm water (1-1/2 cups)
splash vanilla
Mix. Put in well-greased tin. Bake at 190C (375F) for 40 mins, till cake pulls away from the edges of the pan and springs back when touched lightly.


Following the second recipe, baked in two 8" layer tins, this was the result -

I was alarmed by how thin the dough was, and unfortunately adding the liquid ingredients to the dry ingredients resulted in a lot of lumps. By the time I'd sorted those out, the fizzing reaction had stopped, and the layers came out of the oven rather flat. But it was airy and tender nonetheless - and delicious.

So I suggest you add the liquid gradually.