In a pot, heat the heavy cream, milk and one tbsp sugar into warm stage.

In a bowl, beat egg yolks, sugar and corn starch.

Pour half or warm milk into egg mixture. Whisk it well until sugar dissolved. Pour back the egg mixture into the milk in the pot.

Switch on the heat, add vanilla bean/vanilla extract. Keep whisking it until the custard thickens. Test it with the back of wooden spoon.

Prepare the chocolate cake.

In a small bowl, mix yogurt and baking soda. Set aside, let it working. In another bowl, mix the flour and cocoa powder. Set aside. In a reheated bowl, place the water and butter in a bowl. Heat it for 30 seconds. It melts. Remove it out from microwave, add sugar. Let it dissolve.

Add all mixture together in a bowl, the yogurt, dry ingredients and wet ingredients. Whisk them well. Add the chocolate flake. Mix it.

Prepare a microwable bowl (size 500 ml). Brush with some oil or margarine. Pour in the batter into it. Shake a bit to remove the air bubble. Bake in microwave for 3 mins for the 1200 watt microwave. Bake it for 6 mins for the 850 watt microwave. Adjust accordingly please.

Assembly: Slice the chocolate cake as your wish and sprinkle the sugar powder on top of it. Add a scoop of vanilla ice cream. Sprinkle the cookies crumble.