Instructions

• Mash the bananas until mostly smooth with some small chunks remaining. Measure out all dry ingredients (flour, sugar, baking soda, baking powder, cinnamon, nutmeg, and salt) and whisk them together in a medium bowl to distribute the leavening agents evenly. Prepare the streusel topping by combining the ¾ cup flour, brown sugar, cinnamon, and salt in a separate small bowl. Cut the cold butter into ½-inch cubes and add to the streusel mixture, then use a fork or your fingertips to work it into coarse crumbs. Preheat your oven to 425°F.
• In a large bowl, combine the mashed bananas, vegetable oil, room-temperature eggs, and vanilla. Whisk vigorously for about 1 minute until the mixture is well combined and slightly emulsified.
• Pour the dry ingredient mixture into the wet mixture. Using a wooden spoon or spatula, fold everything together with as few strokes as possible until the flour streaks disappear. Fold in the chocolate chips until evenly distributed, then let the batter rest for 15 minutes.
• Place paper liners in every other hole of a standard 12-cup muffin pan. Divide the rested batter evenly among the lined cups, filling each about three-quarters full. Generously top each muffin with the streusel mixture, then sprinkle extra chocolate chips on top.
• Bake at 425°F for 7 minutes, then lower the oven temperature to 350°F and bake for 16-18 minutes longer until a toothpick inserted comes out with a few moist crumbs. Let the muffins cool in the pan for 5 minutes before removing.
• Transfer the muffins to a wire cooling rack and let them cool for at least 20 minutes before serving. If you only have one muffin pan, repeat with the remaining batter for a second batch.