Start by greasing and lining an 8x8 inch square baking tin, then preheat your oven to 200°C (180°C fan) or Gas Mark 6.

Finely chop the dark chocolate and place it in a large mixing bowl.

Melt the unsalted butter and pour it over the chopped chocolate, stirring until the mixture is completely melted.

Add the golden caster sugar to the bowl and mix well to combine.

Incorporate the plain flour and ¼ teaspoon of salt, stirring until everything is well mixed.

Crack in the three large eggs and stir until the batter is smooth and combined.

Pour the brownie batter into the prepared baking tin, spreading it out evenly.

Bake in the preheated oven for about 35 minutes. Note that brownies should remain gooey inside, so a knife test may not be reliable. If using a digital thermometer, the internal temperature should exceed 80°C.

Once baked, allow the brownies to cool completely in the tin.

For the caramel, place the caster sugar in a heavy-bottomed saucepan over medium-high heat.

Stir occasionally to ensure the sugar melts evenly, cooking until it turns a golden-amber color.

Remove the saucepan from the heat and carefully stir in the double cream, unsalted butter, ½ teaspoon of salt, and vanilla extract. Be cautious as the mixture will bubble up.

Return the saucepan to the heat and continue cooking until the caramel reaches 118°C on a food thermometer, which should take around 10 minutes.

Once the caramel has reached the desired temperature, take it off the heat and fold in the cornflakes, ensuring they are all well coated.

Pour the caramel cornflake mixture over the cooled brownie base and spread it out evenly.

Allow the entire dish to cool completely before cutting into squares.