Method
1. Pre-heat oven - 180°C
2. Add milk chocolate, dark chocolate and salted butter to the clean large mixing bowls
3. Melt slowly in double boiler until completely melted then set aside
4. Sift all purpose flour into a clean large mixing bowl
5. Add baking powder to the dry ingredients
6. Sift cocoa powder into the dry ingredients
7. Add caster sugar to the dry ingredients
8. Mix thoroughly until combined
9. Transfer one quarter of dry ingredients to 2 chocolate mixture
10. Fold gently until combined
11. Transfer one quarter of dry ingredients to 2 chocolate mixture
12. Fold gently until combined
13. Transfer one quarter of dry ingredients to 2 chocolate mixture
14. Fold gently until combined
15. Transfer one quarter of dry ingredients to 2 chocolate mixture
16. Fold gently until combined
17. Add egg to a clean small bowl
18. Whisk lightly
19. Transfer content of small bowl to 2 chocolate mixture
20. Fold until combined
21. Line a clean rectangular pan with parchment paper
22. Transfer chocolate mixture to rectangular pan
23. Bake - 25 min, 180°C
24. Remove
25. Let rest - 15 min
26. Serve