Preheat the oven to 350F.

Grease and flour (if needed) a 6 cup capacity bundt pan.  Set pan onto a baking sheet.

In a skillet set over medium heat, melt the butter.

Add the pieces of banana and caramelize in the butter, cooking till turning golden with a touch of brown on each side.  Remove to a bowl and mash finely.  Set aside.

Mix the flour, baking soda, cardamom, cinnamon and salt together in a small bowl.  Set aside.

Place the softened butter and sugar into a stand mixer bowl (or use a hand mixer)  Using the paddle attachment, whip until fluffy, about 5 minutes.

Add the egg and blend well. Fold in the flour mixture and blend to just combine, no further.

Add the sour cream and mashed bananas.  Mix to just combined.  Do not overmix.

Fold in cocoa nibs.

Pour the batter into the bundt pan and smooth the top.  Tap the pan lightly to release any air pockets.

Bake in the lower third of the oven for 60 minutes.  Or until golden on top and a skewer comes out clean.  This cake gets a pretty good rise.  If you find that the batter has risen and the top is starting to turn a tad too brown, feel free to cover with some tin foil, lightly.

Place the bundt pan onto a cooling rack.  After 10-15 minutes you should be able to turn the cake over to release from the bundt pan.

In the meantime, take the Bourbon Caramel Sauce and reheat in a small pot set over medium low heat, till just runny.  Let cool slightly.

Drizzle the cake with the caramel sauce.  I leave the cake on the cooling rack, and place it over a parchment lined baking sheet.  Makes for easy cleanup.