Preheat the oven to 180C (160C fan).

Grease and line your tin.

Put the dark chocolate and butter in a large microwave safe bowl. Microwave in 30 second bursts, stirring between each burst, until melted. Avoid overcooking as this can negatively affect the chocolate.

Add the caster sugar. Stir through with a manual whisk - I say stir as you don’t want to add air but a whisk is still the best tool as it distributes everything quickly .

Add the eggs and vanilla. Stir with the whisk again.

Put the flour through a sieve into the bowl.  Stir to combine.

Pour the brownie batter into the lined tin and level off.

Bake your brownie for 25 minutes until almost done. Make the cornflake topping while the brownies bake.

Put the butter, syrup, sugar and salt in a saucepan. Stir over a medium heat until the butter is melted and you can’t feel sugar granules on the base of the pan.

Put the cornflakes in a bowl, pour the syrup on top and stir until they’re all coated.

Spoon the mixture on top of the brownie and gently press down until the brownie is fully covered with cornflakes.

Return the brownies to the oven and bake for a final 10 mins until the cornflakes are golden and toasted.

Allow the brownies to cool completely in the tin. Once cooled, I like to place them in the fridge for at least an hour, or even overnight, to firm up.

Slice in a 3x4 pattern with a sharp knife and serve.