Preheat oven to 350F with a rack in the center and spray or generously butter and flour a bundt pan.
In a saucepan reduce the coffee down to 1 cup by simmering for about 15-20 minutes. Remove from heat, add the butter and stir until melted. Stir in the cocoa powder and chocolate, mixing until smooth, then set aside to cool, stirring occasionally to let off heat.
In a medium bowl, whisk together the flours, sugar, baking soda, and salt. Set aside.
In a large mixing bowl, combine the eggs, yogurt, buttermilk and maple syrup. Whisk well, until nicely blended and uniform in appearance. Gradually add the (cooled) coffee/chocolate mixture, stirring all the while. Stir until well blended. Add the flour mixture, folding until just blended, using as few strokes as possible.
Transfer the batter to the prepared pan and bake for 35 - 45 minutes if using the bundt pan, or until you press the cake with your index finger and it bounces back. You really don't want to over bake this cake - err on the slightly moist side if anything. Remove from the oven, and turn out onto a cooling rack after seven minutes.
While the cake bakes stir together the caramel sauce. Set aside. Serve warm cake with whiskey caramel.
Notes
You may make this ahead of time and refrigerate for a few days.