Prep a 8inch (20cm x 20cm) square Brownie Pan with baking paper, greasing all sides.
Heat your oven to 180˚ C or 360˚ F.
Place one slab each of the milk & dark chocolate, along with the butter, in a microwave safe dish and microwave for roughly a minute on a 'soften & melt' setting, until melted. Stir to combine and set aside.
In a separate mixing bowl, beat the eggs until they're light & fluffy. You want to beat them really well, with lots of bubbles.
Then add the sugar, and the vanilla essence, and continue to beat until the eggs becomes paler in color.
Gently fold the melted chocolate & butter mix into the eggs, being very careful not to overmix. Try keep as many bubbles as possible, as they trap the sugar and help it to rise to the top of the Brownies while baking, creating a beautiful thin crust on top!
Sift in the cocoa powder, flour and salt, and continue to gently fold the mixture until everything is incorporated and even in color.
Transfer the mixture into the prepped Brownie pan.