Line a square 18cm (7") nonstick cake tin with baking paper.

Put the milk chocolate, butter and golden syrup in a large heatproof bowl.

Melt gently in the microwave (in 30 seconds blasts) or over a bain-marie and stir until melted and smooth. Allow to cool a little - if the chocolate is hot, it'll melt the additions.

Add the marshmallows and two thirds (300g / 10.5oz) of the Maltesers. Stir well until everything is evenly coated.

Tip the mixture into the tray lined with baking paper. Press to level off.

Top with the remaining (150g / 5.5 oz) Maltesers, pressing down lightly.

Place in the fridge for at least 2 hours or overnight to set.

Once set, cut into 16 squares and enjoy.