Dice the beets and place them in a pan. Boil them for 20 minutes until tender. Turn off the heat, drain the beets, and place them back in the pan. Use a hand mixer to blend the beets into a puree.
While the beets are boiling, create your flax eggs by mixing together the ground flax seeds with 9 table spoons water in a small bowl. Place in the fridge for 15 minutes to allow for the mixture to thicken.
Pit the medjool dates and place them in a heatproof bowl. Cover them in boiling water and allow to soak for 10 minutes whilst the beets are boiling. Drain the dates and puree them using the same hand mixer you used to puree the beets, rinsing the mixer in between is not necessary.
Roughly chop the hazelnuts.
Place the flour, cocoa powder and baking powder in a bowl and mix until combined.
Add the beet puree, date puree, flax egg, hazelnut butter and vanilla bean paste and fold together to allow a thick batter to form.
Line a brownie tin with parchment paper and cover the base with chopped hazelnuts. Add the brownie batter and evenly distribute it using a spatula.
Bake your beetroot brownie in a preheated oven at 180 degrees Celsius or .. degrees Fahrenheit for 40-45 minutes.