Take remaining milk in a wide and thick bottom pan.
Turn the heat on medium. Bring the milk to a boil. Do stir occasionally.
Once it starts simmering, add sugar and mix well.
Let it simmer till it thickens slightly (for about 10-12 minutes). Do scrap the side and bottom of the pan using spatula every now and then.
Now add prepared cornstarch mixture and stir well.
Also add milk powder paste and mix.
Keep stirring and cooking for 7-8 minutes or till it becomes thick.
The mixture should coat the back of spoon or spatula.
At that point, turn off the stove.
Remove the thick, sweetened mix mixture into a bowl and let it cool completely.
As it cools it will thicken more. If it looks lumpy after cooling down, you can use wire whisk or hand mixer or blender to break the lumps and make smooth mixture.
Add heavy cream. And mix well.
Now using hand mixer, beat the mixture.
Beat it for about 4-5 minutes or till it gets light and airy.
Now add vanilla paste or vanilla extract (whatever you are using). Stir well to combine.
Pour the mixture into shallow container.
Cover the surface using plastic wrap and make sure that plastic is touching the ice cream mixture.
Pop in the freeze and let it set for 3-4 hours. Within this time, it should be just set still soft.
Remove the container from the freezer, make big slices or cubes.
Add it to the blender. Blend it till the mixture gets smooth and ice crystals are broken.
Pour the mixture back into the container.
Again cover with plastic and it should be touching to the surface.
Keep in the freezer till it is completely set.
At the time of serving, remove the container from the freezer
and let it stand for 2 minutes. Then scoop the vanilla ice cream ans serve