Take a sauce pan, add sugar and water.
Add butter.Let it melt and boil.
It will become frothy and slightly change color. Do not mix, do not use spoon.Just swirl the pan and cook in low flame.
Add vanilla essence. It will become more frothy and the color changes from light shade to dark color.
When it forms a thick sauce and is dark golden in color switch off and immediately add it to popcorn. Do not burn, this is the correct stage.
Mix it , it will form thick threads, don't worry keep mixing. It will be sticky, transfer to a foil or baking sheet.Allow it for 5 mins then separate the chunks.Cool down then store.