Prepare the crust: In a food processor, pulse the coconut into small flakes.
Add the flour, sugar, salt, and ginger, and pulse lightly to combine.
Add the butter and pulse until only pea-sized bits remain visible.
In a small bowl, stir to combine the milk and egg yolk. Add this to dry ingredients and pulse to form a dough.
Spray to coat a 10-inch fluted tart pan with nonstick cooking spray.
Press the dough evenly up the sides and into the bottom of the tart pan.
Prick all over the bottom of the tart with a fork and refrigerate for at least 30 minutes, or until firm.
Preheat the oven to 375 F.
Line the tart pan with aluminum foil and fill it with pie weights or dried beans.
Bake for 20 minutes, then remove the foil and weights and bake for another 8 to 10 minutes, or until the edges are lightly golden brown. Set aside to cool slightly.
Prepare the filling: In a small pot, whisk to combine the eggs, egg yolks, passion fruit puree, sugar, and salt.
Cook over low heat, whisking constantly, until thickened enough to coat the back of a spoon.
Remove from heat, and whisk in the butter.
Strain into a bowl, then whisk in the vanilla and sour cream. Add 1 tablespoon lemon juice for additional acidity, if desired.
Pour into prepared the tart shell.
Reduce the oven temperature to 350 F, and bake for 18 to 20 minutes, or just until very slightly jiggly in the center.
Transfer to a rack to cool completely, then chill at least 2 hours, or until firm.