• 1½ cups mashed, very ripe bananas (about 4 medium bananas)
• ½ cup sugar
• ¼ cup firmly packed light brown sugar
• ½ cup (1 stick) unsalted butter, melted
• ¼ cup whole milk
• 1 large egg
• 1½ cups all-purpose flour
• 1 teaspoon instant espresso powder
• 1½ teaspoons baking soda
• 1 teaspoon salt
• 1 cup (6 ounces) semisweet chocolate chips

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

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

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.

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.

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.

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