Step 1 Preheat oven to 180°C. Grease an 18cm x 28cm rectangular slice pan and line base and sides with baking paper, extending paper 2cm above edge of pan.
Step 2 Place Arnott’s Farmbake Peanut Brownie cookies into bowl of a food processor and process until mixture resembles fine crumbs. Add butter and process until just combined. Press the mixture over the base and side of the prepared pan. Refrigerate until set.
Step 3 Combine condensed milk, golden syrup and peanut butter in a saucepan over medium heat. Cook, stirring, for 8 minutes or until starting to bubble.
Step 4 Spread caramel mixture over prepared base. Bake for 10-12 minutes or until golden. Remove from oven and allow to cool.
Step 5 In the meantime, place chocolate and butter in a medium glass or microwave safe bowl. Place the bowl of chocolate in the microwave for 20 second bursts on medium power until melted, stirring in-between each burst.
Step 6 Pour chocolate over slice. Place in the fridge to chill.