Bitter Chocolate Self-Saucing Pudding Recipe

125 g self raising flour
¼ cup caster sugar
1 tsp cinnamon
2 Tbsp Dutch cocoa powder
80 g bitter dark chocolate, finely chopped
¾ cup milk
1 tsp vanilla extract
50 g butter, melted
1 egg
Topping
125 g brown sugar
2 Tbsp Dutch cocoa powder
1 cup water, boiling