Take a bowl and put egg whites in it. Turn on the electric mixer and keep the whites whisking until they become light and foamy. Keep the mixer on and add 2 tablespoons of sugar. Keep mixing to dissolve it properly.
Take a large sauce pan and pour water, corn syrup and the remaining sugar in it. Cook the mixture on medium heat and bring it boil. Increase the heat and keep stirring until the mixture comes into soft-ball shape. If you are using a candy thermometer then cook the mixture on 240 degrees F. However, do not leave the thermometer more than 10-15 minutes.
Now you need to combine this syrup with egg whites. For that, cover the mixer with a clean kitchen towel and add the syrup into whites slowly. Increase the speed of electric mixer and whisk it at least for 6 minutes. Add vanilla and keep whisking until it starts looking like marshmallow cream.
Set aside to cool, keep it in a sealed jar and then store in the refrigerator for a month.