Preheat oven to 350 degrees. Line 18 standard muffins cups with paper liners or coat with non-stick cooking spray. Set aside.

Melt chocolate and espresso powder in the top of a double boiler. Remove from heat and let cool.

Whisk together flour, sugar, baking soda, salt, cinnamon and nutmeg in a large bowl. Make a well in center of mixture.

Whisk together bananas, eggs, vegetable oil, buttermilk, molasses and vanilla in a medium bowl. Add to the dry ingredients just until moistened.

Scoop 1 1/2 cups of the batter into another medium bowl and stir in the chocolate mixture.

Spoon banana batter into the prepared cups, filling 2/3 full. Make a small well with the back of a spoon in the middle of each cup. Spoon in some of the chocolate batter, then swirl with wooden pick.

Bake for 22-24 minutes or until pick comes out clean when inserted in center of muffin.

Cool for 5 minutes in pan, then remove to wire racks. Serve warm or at room temp.