Preheat oven to 350. Measure the flour by spooning into the measuring cups. Place flour, salt, and baking soda into a bowl and stir to combine.
Place sugar and butter into a large mixing bowl and mix to combine, about 1 minute. Add egg, yogurt, and banana. Mix to blend, then add flour mixture. Blend until moist and fully combined.
Melt chocolate chips in a microwave or over low heat until just melted. Allow to cool slightly. Add 1 cup of the batter to the chocolate and stir until blended.
Grease a bread pan and alternate layers of chocolate and plain batter. Using a knife, run it through the batter to create the swirl.
Bake for 1 hour and 15 minutes or until the bread tests done. Mine took 1 hour and 5 minutes.
