Line a 13 X 9 inch baking pan with foil, allowing ends to create an overhanging edge for easy removal.
In a large bowl, stir together butter and ¾ cup of the brown sugar until just combined. Stir in egg yolks and salt until smooth. Stir in flour to make stiff dough.
Transfer about 2 cups of the dough to the prepared pan. Save the rest for the streusel crumble.
With your hands, press mixture evenly into the bottom of the pan. Prick dough all over with a fork. Refrigerate for 30 minutes until dough is firm.
Preheat oven to 325 degrees. Bake crust for 20 minutes, until crust begins to set but is not brown at all on the edges. Remove from oven and increase oven to 350 degrees.
Spread Strawberry Fig Jam filling evenly over hot crust. Crumble streusel over filling. Bake 20-25 minutes, until streusel is golden and set.
Allow pan to cool 1-2 hours. When bottom of pan is cool, carefully lift from pan using overhang and transfer to a cutting board. Slip lining away from bars by lifting with a metal spatula.