125g Butter
1 cup Brown sugar
1/2 cup white sugar
3 eggs
2 1/2 cups flour
1 tsp vanilla
1/2 cup yoghurt or sour cream
1/4 cup cocoa
2 tsp Baking soda
1 tsp cinnamon
1/2 tsp mixed spice
1/2 tsp salt
3 cups of grated zucchini ( peel them first) If you use marrow, remove the seed from the centre first.
1/2 - 1 cup chocolate pieces

Preheat oven to 175c 
Grease a 25 cm tin ( I used a 23cm tin and baked it for longer)
Cream butter and sugar. Beat in eggs one at a time with a spoon of the measured flour to prevent curdling.
Add vanilla and yoghurt and mix well. Sift dry ingredients together and stir into the butter mixture together with the grated zucchini. Pour into prepared tin. Sprinkle with chocolate pieces.
Cook for 45 minutes for 25cm tin and approx one hour 10 min for a 23 cm tin.

Ice if you choose.