Chocolate Cake and Fermented Milk

Hello, a very good, economical and very easy to make cake. The recipe is taken from a Turkish site and modified a little bit.

Ingredients

• Tray 30×24 cm 
• 2 eggs
• 200g sugar
• 100ml oil or melted butter
• 250 ml fermented milk (buttermilk-lben or rayeb)
• 1 tsp vanilla
• 25g cocoa
• 1 tsp baking powder
• 1/2 tsp baking soda
• 200g flour
• Icing:
• 100g of chocolate
• 2 tbsp oil
• 50g butter