In the best traditions of cookery, this was discovered by accident. I was trying to make a low-fat sponge. In a way, I did. Starting with the Victoria Sponge recipe I pondered what would happen if I removed the butter and replaced it with a jam. Since jam in general is quite sweet, I also removed the sugar. This recipe is basically that.
4 oz / 115g strawberry jam
4 oz / 115g self-raising flour
Preheat oven to Gas Mark 6 / 200 degrees C / 400 degrees F. Mix the ingredients in a bowl. Pour into a greased and lined 7 inch (20.5 cm) tin and bake for about 15 minutes. Turn out onto a wire rack and leave to cool.