Preheat oven to 350 degrees. Mash enough bananas to get 1 1/2 cups. Set aside.

Lightly spoon flour into measuring cups and level. Combine flour, baking soda, and salt. Cream sugar and butter. Add bananas, eggs, and yogurt, beating until just blended.

Add flour mixture. Beat on low until just moistened.

Microwave chocolate chips in a medium bowl for 1 minute, stirring every 20 seconds. Stir until smooth. Cool slightly. Add 1 cup batter to chocolate, stirring until well-combined. Spoon chocolate batter alternately with plain batter (so you have stripes of plain and chocolate batter) in an 8 ½” x 4 ½” loaf pan coated with cooking spray. Swirl batters with a knife.

Bake for 1 hour 15 minutes (set a timer for 1 hour and check on it after that)–the bread is done when golden brown on top and a knife inserted into the center comes out clean. Remove from oven and cool on a wire rack for 15 minutes, then remove from pan and cool completely before slicing. Store any leftovers tightly wrapped in plastic wrap or in an airtight container.