Step 1

Preheat the oven to 350 degrees. Spray a 12-cup muffin pan with nonstick cooking spray.

Step 2

In a medium bowl, stir together the bananas, sugars, butter, milk, and egg.

Step 3

In another medium bowl, whisk together the flour, instant espresso powder, baking soda, and salt. Make a well in the middle of the dry ingredients. Pour the wet ingredients into the well and stir until just combined. Fold in the chocolate chips.

Step 4

Fill each cup about three-quarters full. Bake in the center of the oven for 20 to 25 minutes, until a toothpick inserted in the center of a muffin comes out clean.

Step 5

Move the muffin pan to a cooling rack, and let cool for 15 minutes. After 15 minutes, remove the muffins from the pan and let them finish cooling on the cooling rack.

Step 6

Muffins can be stored in an airtight container for up to 2 days.