Heat oven to 350 degrees. Spray every other muffin cup with cooking spray, and set aside. Place the bananas and vanilla in a food processor, and process until pureed. Transfer the puree to a medium mixing bowl, and whisk in the eggs and buttermilk until just combined. Be careful not to overmix the batter, or the muffins will become too tough . Set aside. In another medium mixing bowl, whisk together the flour, cocoa powder, sugar, baking powder, baking soda, and salt. Using a large spoon, stir in the banana-vanilla mixture until just combined. Spoon the batter into the prepared muffin cups, until its almost to the top. Transfer muffins to the oven to bake until a toothpick inserted into a muffin comes out clean, about 35 minutes. Place muffins on wire rack to cool. Serve warm. Makes 10. Per muffin: 161 calories; 2g fat; 43mg cholesterol; 32g carbohydrate; 119mg sodium; 4g protein; 1g dietary fiber. Source: "Martha Stewart Living Magazine, Feb 1997" S(Formatted for MC5): "by Lynn Thomas - Lynn_Thomas@prodigy.net" Per serving: 147 Calories (kcal); 1g Total Fat; (7% calories from fat); 3g Protein; 31g Carbohydrate; 38mg Cholesterol; 149mg Sodium Food Exchanges: 1/2 Grain(Starch); 0 Lean Meat; 0 Vegetable; 1/2 Fruit; 0 Fat; 1 Other Carbohydrates Recipe by: Martha Stewart Converted by MM_Buster v2.0n.