This fig jam keeps for weeks, so if you like, make it well ahead of time. Try to use lemon thyme, if possible. These bars are good with a dollop of whipped cream.
To make the pastry
Heat the oven to 350°F. In a food processor, grind the walnuts with 2 Tbs. of the sugar until fine; remove and set aside. Put the flour, the remaining 1/4 cup white sugar, the brown sugar, salt, and baking powder in the food processor; process until blended. Add the butter; process until the mixture looks crumbly. Add the egg yolk and vanilla and pulse until mixture is wet and clumping, about 40 seconds (it won't form a ball). Pack two-thirds of the dough into an ungreased 8x8-inch baking dish; set aside the other third. Bake until the dough is lightly browned and keeps a slight indentation when you press it lightly, about 30 minutes.
To make the jam
While the crust is baking, coarsely chop the figs. Put them in a nonreactive skillet with the sugar and thyme and cook over medium-high heat, stirring occasionally, until the juices have reduced and the fruit is tender and thick, about 20 minutes. Discard the thyme sprigs. Stir in the lemon zest, add the lemon juice to taste, and set aside. If not using right away, refrigerate in a closed container.
To assemble the fig bars
In a mixing bowl, crumble together the remaining dough with the reserved walnut and sugar mixture. Gently spread the fig jam on top of the baked crust and sprinkle the dough mixture over the filling. The top will look crumbly. Bake until browned on top, about 40 minutes. Cool completely before you cut into bars 1-1/2 inches square.
nutrition information (per serving):
per 1 1/2-inch square bar;
Photo: Laurie Smith