Roughly chop your marshmallows, meringue kisses and nuts into smaller pieces. Keep some pieces larger if you a more rustic look.
Line a lamington / slice tin with baking paper.
In a microwave safe mixing bowl, empty the packets of white chocolate melts and add the coconut oil. Heat in 30second bursts until the edges are melting but there are still some intact buttons.
Stir to combine the oil and chocolate, until the remaining buttons have dissolved and the mixture is consistent.
Mix in the remaining ingredients, ensuring everything is well coated and the ingredients are evenly distributed.
Pour into the lined tin and flatten out gently as you spread with a spatula. Refrigerate for 4 hours or until set before transferring to a cutting board, slicing & serving.