Preheat oven to 350 degrees. Generously spray mini bundt pan with nonstick cooking spray.
Melt chocolate in a microwave safe bowl for 10 second increments, stirring in between, until smooth. Set aside.
Sift flour, cocoa powder, baking powder and soda, and salt into a bowl.
In the bowl of your mixer, beat melted butter and sugar on medium high speed for 2 minutes.
Add egg and vanilla and beat for an additional 2 minutes.
Stir in melted chocolate.
Add buttermilk and flour mixture and stir until just combined.
Spoon batter into bundt pan and fill ⅔ of the way full.
Bake bundt cakes for 10-17 minutes (10-12 minutes for a small bundt pan and 15-17 minutes for larger mini bundt cakes) or until a knife is inserted and comes out clean.
Cool for 5 minutes in the pan, then invert cakes onto a cooling rack to cool completely.
Once cool, heat caramel sauce and hot fudge in a microwave safe bowl for 30 seconds.
Dip cakes into the warm caramel sauce, the sprinkle with a generous amount of toasted coconut.