For the tarts, add the oats and pecans to a blender and blitz to a fine flour texture.
In a bowl, whisk together the cashew butter, maple syrup, coconut oil and salt. Now pour in the ground oats and pecans and stir to a thick, sticky dough.
Using a silicone cupcake tray or individual silicone cupcake cases, divide the tart dough into 10 pieces. Roll into balls and place one ball in each cupcake hole. Press down firmly to make a cup-shape, working up the sides. Chill in the freezer for 20 minutes.
Meanwhile, melt the chocolate. Add the tofu to a blender along with the melted chocolate and blend until really creamy. Stop to scrape down the sides as necessary and keep going until no lumps remain. Allow the filling to chill for 10 minutes in the fridge.
Remove the tarts from the cases and place on a plate. Using a piping bag or spoon, fill the tart cups with the chocolate mousse filling. Top with a whole pecan and some extra ground pecan and set in the fridge for 10-20 minutes, or eat straight away.
Tarts will last for 5-7 days in an airtight container in the fridge.