Preheat oven to 350°F/180°C.
Lightly spoon flour into dry measuring cups, and level with a knife. Combine the flour, baking soda, and salt, stirring with a whisk.
Place sugar and butter in a large bowl; beat with a mixer at medium speed until well blended (about 1 minute). Add banana, eggs, and yogurt; beat until blended. Add flour mixture; beat at low speed just until moist.
Place chocolate chips in a medium microwave-safe bowl, and microwave at HIGH 1 minute or until almost melted, stirring until smooth. Cool slightly. Add 1 cup batter to chocolate, stirring until well combined. Spoon chocolate batter alternately with plain batter into an 8 1/2 x 4 1/2-inch loaf pan coated with cooking spray. Swirl batters together using a knife. Bake in preheated oven for 1 hour and 15 minutes or until a wooden pick inserted in center comes out clean. Cool 10 minutes in pan on a wire rack; remove from pan. Cool completely on wire rack.
Makes 1 loaf, 16 slices
Date: March 3, 2006