In a stand mixer fitted with the paddle attachment, cream the butter and cream cheese on medium speed for 3 minutes.
In a small bowl, rub the granulated sugar with the lemon zest. Add to the cream cheese mixture, along with the salt and vanilla bean paste. Mix for 2 minutes on medium speed
Sift the flour, hazelnut meal and spices together. Add to the mixture on low speed. Mix until the dough just comes together, about 1 minute. Shape into a rectangular block and chill for 1 hour or overnight.
On a lightly floured surface, roll the dough into a rectangle 1/4 inch thick. Use a 3 1/2-inch round plain or fluted cookie cutter to cut the dough into rounds. Reroll the dough scraps and cut more rounds. You should have 28 to 30 rounds. Chill the dough for about 20 minutes.
Preheat the oven to 350 degrees F.
This dough gets soft very quickly, so work only a few pieces at a time. On a baking sheet lined with parchment, arrange a few of the dough rounds and brush the edges with the egg wash. Drop a small spoonful of the fig jam in the center of each cookie. Top with 2 or 3 toasted hazelnuts if using. Bring up the edges to form a triangle and lightly pinch the edges to seal. Repeat with the remaining rounds. Chill the cookies for 1/2 hour before baking.
Sprinkle each cookie with turbinado sugar and bake for 25 to 28 minutes. Let cool before eating. Store in an airtight container for up to 3 days at room temperature.