1. Preheat oven to 175°C (350°F). Grease and flour a cake tin.
2. Mix together flour, sugar, chocolate, baking soda, baking powder, salt, and cinnamon. Then add eggs and oil, and stir well.
3. Stir in nuts and zucchini until evenly incorporated.
4. Pour batter into tin.
5. Bake for 50 to 60 minutes.
6. Let cake cool completely before serving.