For the base, break 100 g of chocolate into pieces and melt with coconut oil in a hot water bath. Finely crumble the rice cakes and mix them with the melted chocolate. Rinse a tart mould with lift-off base (26 cm Ø) with water. Line with foil. Press the chocolate rice wafers in it to a base, forming a rim. Chill for about 1 hour.
For the ganache, wash the orange hot, dab dry and finely grate the peel. Break the remaining 600 g chocolate into pieces. Melt with "Soya Cuisine" at low heat while stirring. Add the orange zest, except for something to decorate.
Spread the chocolate-orange cream on the rice cake base and smooth it down. Chill the tart for about 4 hours. Carefully lift it out of the tin and sprinkle with the remaining orange peel.