Preheat oven to 400°F. Grease twelve 2 1/2-inch muffin cups; set aside. In a large bowl stir together flour, brown sugar, cocoa powder, baking powder, coffee crystals, baking soda, and salt. Make a well in the center of flour mixture; set aside.

In a 2-cup measure whisk together buttermilk, sour cream, eggs, and butter. Add all at once to flour mixture. Gently stir just until moistened (batter should be lumpy).

Spoon batter into prepared muffin cups, filling each about three-fourths full. Trim ends from bananas and bias-cut each into 6 pieces. Press a banana piece into each (banana will not be covered). Drizzle banana pieces with honey. Bake for 15 minutes or until tops are firm. 

Cool in muffin cups on a wire rack for 5 minutes. Remove from muffin cups. Serve warm. If desired, drizzle with additional honey.