Start by greasing a springform cake tin. In a high-powered blender, blitz the ingredients together for the base until they start to clump or stick together. Press the crust down into the prepared tin, then place in the freezer to firm up while you make the filling.
Place all the ingredients for the tart, into a high-powered blender and process until smooth. Stop to taste and add more sweetener or orange juice, or even Lucy Bee Cacao Powder, if desired. Pour over the tart crust, then pop back in the freezer overnight.
Once ready to serve, remove from the freezer and bring to room temperature for around 20 minutes before cutting into slices. Serve drizzled in raw chocolate sauce and grated orange zest.