1cupmashed bananafrom approximately 2 large or 3 medium overripe bananas
2ouncesunsweetened chocolatemelted and cooled
Preheat oven to 350°F. Prepare muffin pans by lining 12 muffin cups with paper liners.
In a large bowl, whisk together flour, baking soda, and salt. In another bowl, use an electric mixer to beat the butter until smooth, and then beat in the sugar until light and fluffy. Blend in the egg, vanilla, mashed bananas, and sour cream until fully incorporated (batter may look curdled at this point...it will smooth out with addition of flour). Gently mix in the dry ingredients until just blended.
Scoop half of the batter into a second bowl. Stir the melted unsweetened chocolate into one of the bowls of batter until fully incorporated.
Use a spoon (or small cookie scoop) to scoop plain banana batter into half of a muffin liner. Use another spoon to scoop chocolate batter into the other half of the muffin liner. Repeat until all twelve muffin liners are full. (Alternatively, you may layer and/or swirl the batter with a toothpick for marbled muffins.)
Bake muffins for 17 to 20 minutes, until a toothpick inserted in the center just comes out clean. Cool muffins in the pans for 5 minutes before transferring to a wire rack to finish cooling completely.
Recipe can be easily doubled.
For more wholesome muffins, you can always substitute whole wheat pastry flour for the all-purpose flour.