I was thinking of adding a little chilli to the Chocolate Olive Oil Cake. What quantity and variety would you recommend?
Whilst Nigella's Chocolate Olive Oil Cake (from Nigellissima and on the Nigella website) is delicious as it is, Nigella herself is always tweaking recipes and you could certainly experiment with adding some spice to the cake. Chilli and chocolate is a popular combination, however the strength of chilli required is more a matter of personal taste.
We would start by trying dried chilli flakes and if you use around 1/2 teaspoon then you should add some warmth without too much kick. You will need to grind up the flakes a little so that they distribute evenly and you can do this with a pestle and mortar or you could whizz the chilli flakes with some of the sugar until the flakes are more finely ground. Add the ground chillis with the sugar when you make the cake.
From there if you want more heat then you can increase the dried chilli flakes and/or add a deseeded and finely chopped fresh red chilli - we would suggest using a medium heat chilli such as a red Jalapeno, Fresno or Dutch Red.
If you like a slightly spiced chocolate cake then we would also recommend trying Nigella's Christmas-Spiced Chocolate Cake (from Christmas and on the Nigella website) which is gluten free and has a spiced almond topping.