Grease and line a 20cm x 28cm (8 inch x 11 inch) non-stick shallow rectangular cake tin.
Put the dark chocolate and butter in a large mixing bowl. Place in the microwave and cook for 30 seconds, then stir gently. Repeat until the chocolate is just melted.
Add the sugar and gently stir with your whisk.
Next, stir in the eggs, then add the sifted flour and stir together.
Pour half the batter into the prepared tray and level off.
Dot around half the Aero Chocolate Bubbles on top of the batter.
Pour the rest of the batter on top and level off.
Position the remaining Aero Chocolate Bubbles and the Aero bars on top.
Bake for 30 minutes. You can test if it's baked by pushing a skewer into the centre.. If just right, you'll see sticky crumbs.
Place the brownie in its tin on a wire rack to cool completely. I like to then chill mine overnight to get them nice and firm for slicing.
To serve, place on a board and use a sharp serrated knife to trim off the edges, then cut into 12 pieces in a 3 by 4 pattern.