Chocolate Overload Cake

Name: Chocolate Overload Cake
Cuisine: American, World Cuisine
Ingredients: 280g (2⅓ cups) flour (see note 1); 80g (¾ cup) cocoa powder; 1 tsp baking powder; 1½ tsp baking soda; 300g (1½ cups) white sugar; 90g (½ cup) brown sugar; 250ml (1 cup) milk (see note 2); 2 tsp vanilla extract; 180ml (¾ cup) vegetable oil; 3 eggs (large); 250ml (1 cup) hot water; 1 tbsp instant coffee; 150g (½ cup + 3 tbsp) butter (softened); 200g (¾ cup + 2 tbsp) cream cheese; 200g (½ cup + 3 tbsp) Nutella; 250g (2 cups) icing / confectioners' / powdered sugar; Any chocolate or candy you like (and as much as you want)