Place figs and raisons into a bowl, cover with brandy and let sit for 30 minutes, stirring occasionally. Drain, reserving both the brandy and the soaked fruit.
Preheat oven to 350 F.
Whisk together flour, cocoa powder, baking soda and kosher salt in a medium bowl. Whisk together granulated sugar, egg and melted butter in a large bowl until pale; whisk in 1/2 cup of the strained brandy and vanilla. Add flour mixture and whisk to combine. Set batter aside.
To make the caramel: Sprinkle sugar evenly on the bottom of a saucepan over medium heat. Let sugar melt into an amber-colored liquid, stirring or swirling the pan occasionally. As soon as the caramel is a dark amber color, add in the remaining 1/3 cup of strained brandy, whisking carefully until caramel is smooth. Remove from heat and stir in the butter and salt.
Pour caramel into a 9-inch springform pan, then line the bottom with the soaked figs and raisons. Once arranged, pour the chocolate cake batter over the dried fruit and smooth the top.
Place springform pan on a sheet pan and bake for 45-50 minutes, until a toothpick inserted in the center comes out clean. Allow to cool slightly then invert onto a serving tray or platter.