Prepare Tin: Grease and line your baking tin with parchment paper, allowing some overhang for easy removal later.

Create Biscuit Base: Crush the digestive biscuits into fine crumbs. Melt the butter and golden syrup together in a saucepan, stirring gently for 2-3 minutes. Combine with biscuit crumbs.

Melt Chocolates: Break the dark and milk chocolate into pieces and microwave in 30-second bursts until melted.

Combine Mixture: Pour the melted chocolate mixture over the biscuit base, stirring thoroughly.

Set Base: Transfer the mixture into the prepared tin and press down firmly. Refrigerate for about 30 minutes.

Add Aero: Press the Mint Aero Bubbles gently into the top surface of the traybake.

Prepare Topping: Melt the white chocolate and mix in green food coloring, then melt more milk chocolate.

Decorate: Drizzle the melted chocolates alternately over the top and swirl with a cocktail stick.

Chill & Slice: Chill the traybake for an additional 2 hours, then slice into squares and serve.