Moist chocolate cake

100g chocolate, broken up
125g butter, softened
1 1/4 c sugar
3 eggs
1 tsp vanilla
1 1/2 c yoghurt
2 c flour
1/2 tsp baking powder
1 1/2 tsp baking soda
2 tbsp cocoa

Line the bottom of a 23cm ring tin. Butter & dust the sides.
Melt the chocolate over boiling water.
Cream the butter & sugar, add eggs one at a time, then vanilla.
Add yoghurt with the chocolate.
Sift dry ingredients & add.
Pour into tin.
Bake 150C 1 1/2 hours. cool in tine for 5 mins. turn out.