Step 1

Melt butter in a saucepan over low heat. Line a 7cm x 25cm loaf tin with baking paper.

Step 2

Add condensed milk, golden syrup and brown sugar. Stir over low heat until boiling, then simmer for 10 minutes, stirring constantly.

Step 3

Remove from heat and stir in white chocolate.

Step 4

Pour into prepared tin, smoothing over the surface. Allow to cool and refrigerate until firm. Cut into squares.