Gather all your equipment and line the baking tray with parchment paper to prevent sticking.
Chop the dark chocolate into small, even pieces to help it melt smoothly.
Place the chopped chocolate and butter in a saucepan over low heat, stirring gently until the mixture is glossy and completely melted.
Remove the saucepan from heat and stir in the vanilla extract and honey if using, ensuring everything is combined and smooth.
Pour the melted chocolate mixture over the toasted cornflakes in a large bowl, then gently fold with a spatula until the flakes are evenly coated in chocolate.
Transfer the coated cornflakes mixture into your prepared tray, pressing down gently with the back of a spatula or your fingertips to spread and compact it evenly.
Refrigerate the tray for at least 2 hours, or until the mixture is firm and set, with a crackly surface when pressed lightly.
Once set, use a sharp, warm knife to cut the bars into squares or rectangles, wiping the blade clean between cuts for neat slices.
Serve the bars at room temperature for the best texture, enjoying the satisfying crackle of chocolate and crunch of cornflakes with every bite.
