Bring milk to a boil, reduce the flame and keep stirring for 3-4 mins.
Meanwhile, mix corn flour in little water or cooled down milk and pour it into the boiling milk.
Mix it well and keep stirring continuously until the milk is creamy and there is no raw smell/taste of corn flour. Add vanilla essence, mix well and remove from heat. Let this cool down completely.
Add sugar to the mango puree and let it dissolve completely.
In popsicle moulds, first add 2-3 tbsp of mango puree.
Next pour the vanilla milk mixture to the top. Set this in the freezer for 6-8hrs or overnight. If using the popsicle lid, close it right away but if using ice cream sticks, wait for the popsicle to be half set.
To remove the popsicle, run the mould in running water and rest for a couple of minutes. Gently pull it out. Serve immediately.