Marbled Chocolate Banana Bread

I love a good banana bread, and the chocolate makes this one particularly tasty. The bread is moist and freezes well.

Ingredients
2 Cups all - purpose flour
3/4 tsp baking soda
1/2 tsp salt
1 Cup sugar
1/4 Cup butter, softened
1 1/2 Cups mashed ripe banana (about 3 bananas)
2 eggs (or 1/2 cup egg substitute) 
1/3 Cup plain low - fat yogurt
1/2 Cup semisweet chocolate chips
Cooking spray

Directions

1. Preheat oven to 350°.
2. Lightly spoon flour into dry measuring cups, and level with a knife. Combine the flour, baking soda, and salt, stirring with a whisk.
3. Place sugar and butter in a large bowl; beat with a mixer at medium speed until well blended (about 1 minute). Add banana, egg substitute, and yogurt; beat until blended. Add flour mixture; beat at low speed just until moist.
4. 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 at 350° 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.