Place the clotted/double cream, caster sugar, golden syrup, and vanilla extract in a large saucepan and heat gently, stirring until the sugar dissolves.
Turn the heat up and bring to a rolling boil, cover and continue boil for 3 minutes!
Uncover and continue to boil until the temperature reaches 116°C (Soft Ball Stage).
Test using a sugar thermometer, or see notes below*. It shouldn't take too long to reach the temperature! (A rolling boil is when its constantly boiling but not rising up the pan to overflow - if it starts to overflow the temperature is far too high!)
When the mixture is hot enough, remove from the heat and beat until the mixture becomes thick, and more matte - you will know when its changing as it'll be thicker and the colour will change slightly as you beat it (this could take up to 10 minutes).
Once beaten, add in 75% of the Oreos and mix through evenly.
Pour into the tin and sprinkle/press the rest of the chopped Oreos into the top of your fudge.
Leave to set at room temperature for around 6 hours - sometimes it can take overnight!
Chop up into small pieces and enjoy!
Notes
*If you don't have a sugar thermometer, you can see if the fudge is ready by dropping a little into a cup of cold water. If a soft ball, squeezable piece of fudge is formed, it is ready. But BE CAREFUL – it is EXTREMELY hot!
If you don't like Oreos you could easily change it out for another biscuit - but Oreos are definitely my fave!