Preheat your oven to 180 degrees C (160 degrees C if using fan forced). Grease a 5cm-deep 20 x 26cm roasting pan and line it with baking paper.

Combine the pistachios and cranberries in a bowl, saving a couple of tablespoons for garnish.

Crush the Weet-Bix biscuits into a fine crumb in a separate bowl and mix in the shredded coconut, self-raising flour, brown sugar, and pistachio-cranberry mixture.

Fold in the melted butter, spread the mixture into the prepared pan, and press down firmly.

Bake for 15 minutes or until golden. Let it cool.

In a saucepan, combine caster sugar and 125ml of water and melt over low heat.

Increase the heat until it bubbles.

In a small bowl, soak the gelatine in 80ml of water before adding it to the sugar mixture and stirring until blended.

Allow the mixture to cool slightly, then transfer to a stand mixer, add vanilla, and whisk on various speeds for a total of 17 minutes, incorporating pink food coloring gel.

Pour the marshmallow topping over the Weet-Bix base and refrigerate for about 6 hours until set.

Once set, slice into squares and top with whipped cream, reserved cranberries, and coconut.