Instructions

1. Line a square 23cm tin with parchment paper, set aside.
2. Place 400g of the chopped white chocolate in a large heat-resistant bowl. Set the bowl over a pot of steaming water, making sure the bottom of the bowl doesn’t touch the water. Allow to melt slowly, stirring occasionally. When about 75% of the chocolate has melted, remove from heat and allow the residual heat to melt the remaining chocolate. Stir until melted and smooth.
3. Add the chopped Oreo cookies, dried cranberries, mini marshmallows and pistachio nuts (if using) and stir to mix until all of the ingredients are coated in white chocolate.Pour mixture into prepared tin then spread the mixture in the tin and flatten out evenly with a spatula or back of a large spoon.
4. Melt the remaining 100g white chocolate and drizzle messily over the top with a spoon. Refrigerate until set, about 1 hour. Lift the chilled square out of the tin and place on a chopping board. Use a large sharp knife to cut into squares.
5. Store in an airtight container at room temperature for up to 7 days.