Preheat 180°C. Line a small baking dish with baking paper.
Prep beetroot. Place butter, caster sugar, cocoa and grated beetroot in a medium pot on medium heat. Stir continuously, until butter has melted. Remove from heat.
In a large bowl, whisk eggs with electric beaters for about 3 minutes until pale and fluffy.
Pour chocolate mixture and flour into eggs and mix quickly to combine.
Transfer to prepared dish and bake for 30 minutes, the top should be cracked and the brownie gooey in the middle.
Serve in bowls with cream or ice cream.