Grease and line a 20cm x 20cm square baking tray.

Melt the white chocolate in a glass bowl over a pan of simmering water or by microwaving.

Add the butter and stir until smooth.

Reserve ⅓ of the mixture.

Mix in the pistachios, biscuit pieces and mini mallows to the remaining mixture.

Tip the mixture into the tin and smooth down the top.

Pour over the reserved chocolate mixture.

Arrange the Party Ring Minis on the topping to decorate.

Press down gently to fix into chocolate.

Chill in the fridge for at least 2 hrs or preferably overnight, until set.