Chocolate Cornflour Pudding : Busy day pudding

Ingredients -

Granulated sugar - 1/2 cup
Cocoa powder - 3 tbsp
Cornflour - 1/4 cup
Salt - a pinch
Milk - 2 3/4 cup
Butter - 2 tbsp
vanilla essence - 1/2 tsp

Method - 
1. Take a pan and put the coco powder, sugar, cornflour and 
    salt, mix it all.
2. Pour the milk in it, heat it on a low flame, stirring it                            continuously, to avoid any lumps.
3. Bring it to boil, cook until mixture is thick enough to
    coat the back of a spoon.
4. Remove from heat and put the butter and vanilla essence,     
    let it come to room temperature.
5. Refrigerate, serve it chilled, and don't forget to sprinkle
    some choco chips before serving.