Preparation

Step 1: Prepare the Base

1. Line a 20 cm × 20 cm square baking tin with baking paper, ensuring there’s an overhang on the sides for easy removal later.
2. Crush the digestive biscuits into fine crumbs using a food processor or by placing them in a sealed plastic bag and bashing with a rolling pin.
3. In a saucepan over low heat, melt the unsalted butter and golden syrup together, stirring until fully combined.
4. Add the chopped dark or milk chocolate to the saucepan, stirring continuously until the chocolate has melted and the mixture is smooth.
5. Pour in the sweetened condensed milk, mixing well to combine all the ingredients into a cohesive mixture.
6. Remove the saucepan from heat and fold in the crushed biscuits, chopped Mint Aero bars, and, if using, the mini marshmallows or white chocolate chips. Stir until all components are evenly distributed.
7. Transfer the mixture into the prepared baking tin, pressing it down firmly with the back of a spoon to create an even layer.
8. Refrigerate for about 1 hour, or until the base is firm to the touch.

Step 2: Add the Topping

1. Once the base has set, sprinkle additional chopped Mint Aero pieces evenly over the top, pressing them gently into the surface to adhere.
2. Return the traybake to the refrigerator for another 30 minutes to ensure the topping sets properly.

Step 3: Serve

1. Remove the traybake from the tin using the overhanging baking paper and place it on a cutting board.
2. Cut into 16 equal squares using a sharp knife. For cleaner cuts, warm the knife blade under hot water and wipe dry before slicing.
3. Serve chilled or at room temperature, depending on your preference.