Preheat oven to 190.
Sift 375g self raising flour, 25g cocoa powder and 1 tsp baking powder into a large bowl. Mix in 100g choc chunks and 175g caster sugar.
Lightly whisk 2 large eggs, 175ml sunflower oil and 175ml milk in a large jug, then pour this in and mix briefly with a metal spoon.
Divide mixture in cake cases, bake for 25 mins, then leave to cool in the tray before removing.
Variation: use 400g flour and 1/2 tsp baking powder, no cocoa, and use white choc chunks and 100g raspberries.
OR use 375g flour and no cocoa, and use 2 mashed bananas and 100g mini fudge chunks
OR Use 250g plain flour, 25g cocoa powder and 4 tsp baking powder with 150g sugar, 175ml milk, 100ml olive oil and 75g choc chunks