Sift the flour, salt, baking powder and sugar into a bowl and mix well.
Splash in the oil until all is incorporated. Leave the lumps in.
Mix the vinegar with the water and add it to a dough. Mix it without applying much force. Form it into a ball of dough.
Transfer the dough to a piece of plastic. Wrap the dough in plastic foil, keeping enough room to roll it out.
Roll or press the dough flat with a rolling pin, while still wrapped in plastic, to form a circle of about 20 x 0.5 cm.
Place the dough in the plastic on a plate. Leave in the refrigerator for one hour to rest.
For the filling
Preheat the oven to 180 degrees Celsius.
Cut the figs into 8 - 10 wedges. Grind a 100 grams of the walnuts with the dates and maple syrup to a thick paste.
Remove the dough from the refrigerator and grease a 20 cm pie form or springform. Place the dough from the plastic in the pie pan and press it against the sides with your fingertips. A raised edge of 1.5 cm is sufficient.
Spread the nut paste over the pastry base with wet fingers. Place the fig wedges on top in circles. Sprinkle with the rest of the nuts.
Bake the fig cake for 30 minutes in the center of the oven.