Melt the butter in a heavy-based saucepan
Add the sugar, syrup, condensed milk and milk.
Heat very gently until all the ingredients have dissolved.
Bring to the boil, stirring constantly.
Continue to heat, stirring gently until the mixture has reached 115°C/240°F,
Using a sugar thermometer to check the tempterature or test as follows:
Until a teaspoonful of the mixture forms a soft ball when dropped
into cold water
Remove from the heat
add the vanilla essence
Beat well until thick and creamy.
Pour into shallow greased tins (pans)
Mark into squares with a knife.
Leave to cool and set.
Cut into pieces