Mix the flour, cocoa and salt in a bowl. Add the oil, maple syrup and water and mix to produce a dough. Knead the dough on a lightly floured surface for approx. 5 mins. until you can form it into a ball. Wrap the dough in cling film and chill for approx. 1 hr.
Soak the cashews and hazelnuts in water for approx. 4 hrs. Drain the nuts, place in a blender/mixer with the other filling ingredients and purée. Cover the filling and chill for approx. 1 hr.
Shaping and cooking the ravioli
Halve the dough and knead both halves well. Roll out both halves to form thin rectangular sheets. Place the first sheet over the ravioli mould. Spoon in the filling. Carefully place the second sheet of pasta over the mould and roll with a rolling pin to seal the edges, pressing down firmly.
Bring the water and sugar to the boil in a large pan and cook the ravioli in batches for 8-10 mins.