Line an 8-cup-capacity metal pudding steamer with plastic wrap, extending plastic wrap 2cm over edge of steamer.
Place ice-cream in a large bowl. Set aside for 10 minutes to soften (ice-cream should not be melted).
Meanwhile, roughly chop 1 mango. Using a sharp knife, finely shred 1/2 of the chocolate. Add chopped mango and shredded chocolate to ice-cream. Stir to combine. Spoon mixture into prepared steamer. Smooth top. Top with cookies, pressing gently to secure. Cover surface with plastic wrap. Freeze overnight or until firm.
Meanwhile, make Macadamia Praline: Spread macadamias on a baking tray lined with baking paper. Combine sugar and 1/2 cup cold water in a saucepan over medium heat. Cook, stirring, until sugar is dissolved. Bring to the boil. Boil, without stirring, for 8 to 10 minutes or until mixture turns golden, brushing down side of pan with cold water if sugar crystals start to form. Working quickly, pour toffee over macadamias on tray. Stand for 15 minutes or until set. Break praline into shards.
Chop remaining chocolate and place in a small microwave-safe bowl. Microwave on MEDIUM (50%), stirring with a metal spoon every 30 seconds, for 1 minute to 1 minute 30 seconds or until melted and smooth. Thinly slice remaining mango. Turn pudding onto a plate. Carefully peel away plastic wrap. Top pudding with mango, praline and chocolate curls. Drizzle with melted chocolate. Serve immediately.