For the Tart Shells
For the Custard
1For the Tarts Shells: Place nuts, coconut, salt, dates, water, date syrup and vanilla bean seeds in a food processor and process until quite fine and mixture is sticky. Divide between pans. use wet hands if you need to. At this point the tartlets can be refrigerated overnight but refrigerate for 30 minutes before baking, regardless.
2Remove tart pans from refrigerator and poke a couple holes in the base with the tines of a fork to prevent the crusts form rising during baking. Bake the tartlets at 350°F for about 14-16 minutes or until crusts begin to darken around the edges and the base seems done. (In my oven, this is exactly 14 minutes). If your oven bakes a little unevenly or has hot spots, spin the baking sheet around halfway through total baking time. When done, remove from the oven and cool the shells in their pans on the baking sheet. Cover the shells in their pans with saran wrap and freeze or refrigerate.
For the Custard
1Process everything except the fruit and pistachios or hazelnuts (first 6 ingredients) in a high-powered blender until smooth. Transfer the mixture to a saucepan and cook, stirring constantly, until thickened. This should only take a few minutes. Pour the thickened custard into a clean bowl and place saran wrap or sheet of parchment cut to size directly on the surface of the filling. Refrigerate until completely cool and set.
1ASSEMBLY When ready to serve, place one tart shell on each of 8 plates. (If you have made the custard ahead, you will need to whisk it again before using). Spoon or pipe some of the custard into each tart shell and decoratively arrange fruits and chopped nuts on top. Serve at once. (In the photos, the tarts are topped with fresh blackberries, a couple of satsuma orange wedges, pomegranate seeds and roasted chopped pistachios)