Instructions:
- Line a 9x9 inch (23x23 cm) baking tin entirely with baking parchment, ensuring an overhang on two sides to act as handles. Set aside.
- Lightly crush the cornflakes in a large bowl—aim for mostly whole flakes mixed with smaller pieces for texture.
- In a medium saucepan over medium-low heat, combine the butter, sugar, and golden syrup. Stir continuously until the butter is fully melted and the sugar has completely dissolved (about 2–3 minutes). Do not allow the mixture to boil vigorously.
- Whisk in the flour quickly until the mixture is smooth. Immediately remove the saucepan from the heat.
- Pour the hot syrup mixture over the prepared cornflakes in the large bowl. Fold gently but thoroughly with a spatula until every flake is completely coated in the glossy mixture.
- Transfer the coated flakes into the lined tin. Using the back of a damp spoon or lightly floured hands, press the mixture down firmly and evenly across the base to create a compact layer.
- Melt the chocolate chips with the coconut oil (if using) either in a heatproof bowl set over simmering water (bain-marie) or carefully in the microwave in 30-second bursts. Stir until completely smooth.
- Pour the melted chocolate evenly over the pressed cornflake base. Use a spatula to spread it smoothly to the edges.
- Place the tin in the refrigerator for a minimum of 1 hour, or until the chocolate topping is fully hardened.
- Use the parchment overhang handles to lift the entire block onto a cutting board. Slice cleanly into squares using a sharp knife, wiping the blade between cuts for the neatest finish.