Place the chocolate chips in a microwave safe bowl and microwave at 15 second intervals, stirring each time,  until smooth and melted.  Set aside.

In a large bowl, cream sugar or SPLENDA®  with the butter. Beat in eggs one at a time.

Add bananas, milk, and lemon juice to the mixture and blend together.

In another bowl, whisk together the flour, baking powder, baking soda, and salt. Add the flour mixture to wet mixture and stir until just combined.

Remove 1 cup of the banana bread batter and mix in with the melted chocolate.  Stir until well combined.

Grease a large 8 1/2 x 4 1/2-inch  loaf pan. Spoon chocolate batter alternately with plain batter into an 8 1/2 x 4 1/2-inch loaf pan. Swirl batters together using a knife. Bake at 350 degrees for 1 hour.