Place the Arnotts Mint Slice biscuits into a food processor and process until reduced to fine crumbs.

Add the sweetened condensed milk and cocoa powder, processing until the mixture forms a ball.

Transfer the mixture to a bowl and refrigerate for about 10 minutes.

Line a baking tray with baking paper.

Roll 2 teaspoonfuls of the chocolate mixture into balls and place them on the prepared tray.

Refrigerate the balls for another 10 minutes.

Place the dark choc melts in a microwave-safe bowl and microwave on medium, stirring every minute until smooth, about 2-3 minutes.

Dunk each chilled ball into the melted chocolate, allowing excess to drip away.

Return the chocolate-coated balls to the tray and top each with a slice of Aero peppermint block.

Let them sit for about 5 minutes to set.