Line a 20cm tin with baking paper, or a muffin tin with patty pan cases (depending on the size of the piece of fudge you would like)
Chop your white chocolate into small pieces, and set aside.
In a saucepan, melt the butter. Once melted, turn the heat down to low.
To the melted butter, add the condensed milk, golden syrup and brown sugar.
Stir until well combined and allow the mixture to gently reach boiling point. From here, you need to stir the mixture continuously for 10 minutes. After this time, your mixture will be a lovely golden colour.
Turn off the heat, and stir through the white chocolate until the mixture is smooth.
At this point, you'll need to work quickly - transfer the mixture into the prepared tin/patty pan cases. It will start to set as it cools so time is of the essence here!
Allow the mixture to cool before refrigerating for at least three hours. Enjoy!