Line the bottom and sides of the 3.5L slow cooker insert with baking paper and spray with the cooking oil.
Puree the beetroot, then, in a large bowl, stir together the pureed beetroot, melted butter, sugar and vanilla. Add the eggs, one at a time, and stir each one in well.
In a separate bowl, stir together the flour, cocoa powder, baking powder and salt.
Pour the dry ingredients into the wet and gently stir to combine, being careful not to over-mix.
Spoon the batter into the prepared slow cooker insert. Using a wet spoon, spread the batter to the edges and level evenly.
Put the lid on the slow cooker and set to low for 2 ½ hours.
When cooked, let the cake cool slightly in the insert, then carefully remove and allow the cake to cool fully on a wire rack. Top with the beetroot vanilla topping and grated chocolate.
Whip the cream and sugar together until thick. Add the vanilla and beetroot juice and whip again until all combined.
