In a large mixing bowl, use a handheld mixer to cream together room temp. butter and brown sugar until light and fluffy. On medium speed, mix in apple cider vinegar, orange zest, and vanilla extract. Add flour, baking soda, spices, and salt. Use a wooden spoon or spatula to combine until a soft dough forms. You may need to use your hands to press the dough together.

Form dough into a disc and tightly wrap in plastic wrap. Refrigerate for 2 hours.

While the dough rests, make the filling. In a food processor, combine soaked and drained figs, applesauce, orange zest, and vanilla extract. Process until a smooth paste forms. Transfer to a glass jar or container and refrigerate until the dough is done resting. 

Preheat the oven to 350°F. Line a large baking sheet with parchment paper. On a lightly floured surface, roll out the dough to about a 15" square. Cut square in half to make two 7.5x15" rectangles. Spread about 1-inch-wide strip of fig filling down the center of each portion. Fold over one of the long sides of the dough to cover the filling and roll gently to seal (almost like a cinnamon roll). Gently flatten each bar with your fingertips then transfer to the prepared baking sheet.

Bake fig bars until puffed and firm without any significant browning, about 18 minutes. Immediately cut into 1-inch pieces with a very sharp knife or bench scraper. Transfer to an airtight container, with a paper towel between each layer and on top. Per Serious Eats, "this will steam the cookies and retain moisture for them to reabsorb, creating a uniquely soft and cakey texture" Cover for at least 6 hours before serving (very important or else they will be dry!).